A vulnerability in the mesh code of Cisco Wireless LAN Controller (WLC) software could allow an unauthenticated, remote attacker to impersonate a WLC in a meshed topology. The vulnerability is due to insufficient authentication of the parent access point in a mesh configuration. An attacker could exploit this vulnerability by forcing the target system to disconnect from the correct parent access point and reconnect to a rogue access point owned by the attacker. An exploit could allow the attacker to control the traffic flowing through the impacted access point or take full control of the target system. This vulnerability affects the following products running a vulnerable version of Wireless LAN Controller software and configured for meshed mode: Cisco 8500 Series Wireless Controller, Cisco 5500 Series Wireless Controller, Cisco 2500 Series Wireless Controller, Cisco Flex 7500 Series Wireless Controller, Cisco Virtual Wireless Controller, Wireless Services Module 2 (WiSM2). Note that additional configuration is needed in addition to upgrading to a fixed release. Cisco Bug IDs: CSCuc98992 CSCuu14804.

An Authentication Bypass vulnerability in Cisco WebEx Meetings Server could allow an unauthenticated, remote attacker to access limited meeting information on the Cisco WebEx Meetings Server. More Information: CSCvd50728. Known Affected Releases: 2.6 2.7 2.8 CWMS-2.5MR1 Orion1.1.2.patch T29_orion_merge.

A vulnerability in the Border Gateway Protocol (BGP) Bidirectional Forwarding Detection (BFD) implementation of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to bypass the access control list (ACL) for specific TCP and UDP traffic. More Information: CSCvc68229. Known Affected Releases: 9.6(2). Known Fixed Releases: 99.1(20.1) 99.1(10.2) 98.1(12.7) 98.1(1.49) 97.1(6.58) 97.1(0.134) 96.2(0.109) 9.7(1.1) 9.6(2.99) 9.6(2.8).

A vulnerability in the web-based GUI of Cisco Mobility Express 1800 Series Access Points could allow an unauthenticated, remote attacker to bypass authentication. The attacker could be granted full administrator privileges. The vulnerability is due to improper implementation of authentication for accessing certain web pages using the GUI interface. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web interface of the affected system. A successful exploit could allow the attacker to bypass authentication and perform unauthorized configuration changes or issue control commands to the affected device. This vulnerability affects Cisco Mobility Express 1800 Series Access Points running a software version prior to 8.2.110.0. Cisco Bug IDs: CSCuy68219.

A vulnerability in the web-based management interface of Cisco Firepower Management Center (FMC) could allow an unauthenticated, remote attacker to bypass authentication and execute arbitrary actions with administrative privileges on an affected device. The vulnerability is due to improper handling of Lightweight Directory Access Protocol (LDAP) authentication responses from an external authentication server. An attacker could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to gain administrative access to the web-based management interface of the affected device.

Cisco Small Business IP phones with SPA 500 series firmware 7.4.9 and earlier do not require authentication for Push XML requests, which allows remote attackers to make telephone calls via an XML document, aka Bug ID CSCts08768.

A vulnerability in the REST API of the web-based user interface (web UI) of Cisco IOS XE 3.1 through 16.5 could allow an unauthenticated, remote attacker to bypass authentication to the REST API of the web UI of the affected software. The vulnerability is due to insufficient input validation for the REST API of the affected software. An attacker could exploit this vulnerability by sending a malicious API request to an affected device. A successful exploit could allow the attacker to bypass authentication and gain access to the web UI of the affected software. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS XE Software, if the HTTP Server feature is enabled for the device. The newly redesigned, web-based administration UI was introduced in the Denali 16.2 Release of Cisco IOS XE Software. This vulnerability does not affect the web-based administration UI in earlier releases of Cisco IOS XE Software. Cisco Bug IDs: CSCuz46036.

Cisco Video Surveillance Manager (VSM) before 7.0.0 does not require authentication for access to VSMC monitoring pages, which allows remote attackers to obtain sensitive configuration, archive, and log information via unspecified vectors, related to the Cisco_VSBWT (aka Broadware sample code) package, aka Bug ID CSCsv40169.

The sensor in Cisco Intrusion Prevention System (IPS) 7.0 and 7.1 allows remote attackers to cause a denial of service (file-handle exhaustion and mainApp hang) by making authentication attempts that exceed the configured limit, aka Bug ID CSCto51204.

Cisco TelePresence Manager 1.2.x through 1.6.x allows remote attackers to bypass authentication and invoke arbitrary methods via a malformed SOAP request, aka Bug ID CSCtc59562.

The Java Servlet framework on Cisco TelePresence Recording Server devices with software 1.6.x before 1.6.2 and Cisco TelePresence Multipoint Switch (CTMS) devices with software 1.0.x, 1.1.x, 1.5.x, and 1.6.x does not require administrative authentication for unspecified actions, which allows remote attackers to execute arbitrary code via a crafted request, aka Bug IDs CSCtf42005 and CSCtf42008.

Cisco TelePresence Recording Server devices with software 1.6.x do not require authentication for an XML-RPC interface, which allows remote attackers to perform unspecified actions via a session on TCP port 8080, aka Bug ID CSCtg35833.

May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and fixed after the was disclosed in February 2026. This new advisory is for a new vulnerability in the control connection handshaking. The section of this advisory includes Show Control Connections guidance to help with system checks.  A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to the affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric.

The Mobile User Security (MUS) service on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.3(2) does not properly authenticate HTTP requests from a Web Security appliance (WSA), which might allow remote attackers to obtain sensitive information via a HEAD request, aka Bug ID CSCte53635.

A vulnerability in Cisco Duo Two-Factor Authentication for macOS could allow an authenticated, physical attacker to bypass secondary authentication and access an affected macOS device. This vulnerability is due to the incorrect handling of responses from Cisco Duo when the application is configured to fail open. An attacker with primary user credentials could exploit this vulnerability by attempting to authenticate to an affected device. A successful exploit could allow the attacker to access the affected device without valid permission.

A vulnerability in the request authentication validation for the REST API of Cisco SD-WAN vManage software could allow an unauthenticated, remote attacker to gain read permissions or limited write permissions to the configuration of an affected Cisco SD-WAN vManage instance. This vulnerability is due to insufficient request validation when using the REST API feature. An attacker could exploit this vulnerability by sending a crafted API request to an affected vManage instance. A successful exploit could allow the attacker to retrieve information from and send information to the configuration of the affected Cisco vManage instance. This vulnerability only affects the REST API and does not affect the web-based management interface or the CLI.

A vulnerability in the CLI console login authentication of Cisco Nexus 9300-FX3 Series Fabric Extender (FEX) when used in UCS Fabric Interconnect deployments could allow an unauthenticated attacker with physical access to bypass authentication. This vulnerability is due to the improper implementation of the password validation function. An attacker could exploit this vulnerability by logging in to the console port on an affected device. A successful exploit could allow the attacker to bypass authentication and execute a limited set of commands local to the FEX, which could cause a device reboot and denial of service (DoS) condition.

The web interface on the Cisco Scientific Atlanta WebSTAR DPC2100R2 cable modem with firmware 2.0.2r1256-060303 allows remote attackers to bypass authentication, and reset the modem or replace the firmware, via a direct request to an unspecified page.

The System Configuration Protocol (SCP) core messaging interface in Cisco Prime Network Registrar 8.2 before 8.2.3.1 and 8.3 before 8.3.2 allows remote attackers to obtain sensitive information via crafted SCP messages, aka Bug ID CSCuv35694.

The XML API in TelePresence Codec (TC) 7.2.0, 7.2.1, 7.3.0, 7.3.1, 7.3.2, 7.3.3, 7.3.4, and 7.3.5 and Collaboration Endpoint (CE) 8.0.0, 8.0.1, and 8.1.0 in Cisco TelePresence Software mishandles authentication, which allows remote attackers to execute control commands or make configuration changes via an API request, aka Bug ID CSCuz26935.

Cisco NX-OS 6.0(2)U6(1) through 6.0(2)U6(5) on Nexus 3000 devices and 6.0(2)A6(1) through 6.0(2)A6(5) and 6.0(2)A7(1) on Nexus 3500 devices has hardcoded credentials, which allows remote attackers to obtain root privileges via a (1) TELNET or (2) SSH session, aka Bug ID CSCuy25800.

A vulnerability in Web Authentication (WebAuth) clients for the Cisco Wireless LAN Controller (WLC) and Aironet Access Points running Cisco IOS Software could allow an unauthenticated, adjacent attacker to bypass authentication and pass traffic. The vulnerability is due to incorrect implementation of authentication for WebAuth clients in a specific configuration. An attacker could exploit this vulnerability by sending traffic to local network resources without having gone through authentication. A successful exploit could allow the attacker to bypass authentication and pass traffic. This affects Cisco Aironet Access Points running Cisco IOS Software and Cisco Wireless LAN Controller (WLC) releases prior to 8.5.110.0 for the following specific WLC configuration only: (1) The Access Point (AP) is configured in FlexConnect Mode with NAT. (2) The WLAN is configured for central switching, meaning the client is being assigned a unique IP address. (3) The AP is configured with a Split Tunnel access control list (ACL) for access to local network resources, meaning the AP is doing the NAT on the connection. (4) The client is using WebAuth. This vulnerability does not apply to .1x clients in the same configuration. Cisco Bug IDs: CSCvc79502, CSCvf71789.

Session fixation vulnerability in Cisco Secure Access Control System (ACS) allows remote attackers to hijack web sessions via unspecified vectors, aka Bug ID CSCud95787.

The guest portal in Cisco Identity Services Engine (ISE) 3300 1.2(0.899) does not restrict access to uploaded HTML documents, which allows remote attackers to obtain sensitive information from customized documents via a direct request, aka Bug ID CSCuo78045.

Cisco RV110W, RV130W, and RV215W devices have an incorrect RBAC configuration for the default account, which allows remote authenticated users to obtain root access via a login session with that account, aka Bug IDs CSCuv90139, CSCux58175, and CSCux73557.

Cisco Prime Collaboration Assurance before 11.0 has a hardcoded cmuser account, which allows remote attackers to obtain access by establishing an SSH session and leveraging knowledge of this account's password, aka Bug ID CSCus62707.

Cisco Wireless LAN Controller (WLC) devices with software 7.6.x, 8.0 before 8.0.121.0, and 8.1 before 8.1.131.0 allow remote attackers to change configuration settings via unspecified vectors, aka Bug ID CSCuw06153.

Cisco EPC3928 devices with EDVA 5.5.10, 5.5.11, and 5.7.1 allow remote attackers to bypass an intended authentication requirement and execute unspecified administrative functions via a crafted HTTP request, aka Bug ID CSCux24941.

Race condition in the Firewall Authentication Proxy feature in Cisco IOS 12.0 through 12.4 allows remote attackers to bypass authentication, or bypass the consent web page, via a crafted request, aka Bug ID CSCsy15227.

Cisco Adaptive Security Appliances (ASA) 5500 Series and PIX Security Appliances 7.1(1) through 7.1(2)82, 7.2 before 7.2(4)27, 8.0 before 8.0(4)25, and 8.1 before 8.1(2)15, when AAA override-account-disable is entered in a general-attributes field, allow remote attackers to bypass authentication and establish a VPN session to an ASA device via unspecified vectors.

The encryption functionality in the Virtual Supervisor Module (VSM) to Virtual Ethernet Module (VEM) communication component in Cisco NX-OS on the Nexus 1000V does not properly authenticate VSM/VEM packets, which allows remote attackers to disable packet-level encryption and integrity protection via crafted packets, aka Bug ID CSCud14710.

Unspecified vulnerability in the Web Server in Cisco Unified MeetingPlace Web Conferencing 6.0 before 6.0(517.0) (aka 6.0 MR4) and 7.0 before 7.0(2) (aka 7.0 MR1) allows remote attackers to bypass authentication and obtain administrative access via a crafted URL.

A vulnerability in the TACACS+ authentication, authorization and accounting (AAA) feature of Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an unauthenticated, remote attacker to bypass authentication and log in to an affected device as an administrator. This vulnerability is due to incomplete validation of user-supplied input that is passed to an authentication script. An attacker could exploit this vulnerability by injecting parameters into an authentication request. A successful exploit could allow the attacker to bypass authentication and log in as an administrator to the affected device.

Multiple vulnerabilities in Cisco BroadWorks CommPilot Application Software could allow an authenticated, remote attacker to delete arbitrary user accounts or gain elevated privileges on an affected system.

A vulnerability in the Cisco REST API virtual service container for Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass authentication on the managed Cisco IOS XE device. The vulnerability is due to an improper check performed by the area of code that manages the REST API authentication service. An attacker could exploit this vulnerability by submitting malicious HTTP requests to the targeted device. A successful exploit could allow the attacker to obtain the token-id of an authenticated user. This token-id could be used to bypass authentication and execute privileged actions through the interface of the REST API virtual service container on the affected Cisco IOS XE device. The REST API interface is not enabled by default and must be installed and activated separately on IOS XE devices. See the Details section for more information.

Cisco Adaptive Security Appliances (ASA) 5500 series devices, and the ASA Services module in Cisco Catalyst 6500 series devices, with software 7.0 before 7.0(8.13), 7.1 and 7.2 before 7.2(5.3), 8.0 before 8.0(5.24), 8.1 before 8.1(2.50), 8.2 before 8.2(5), 8.3 before 8.3(2.18), 8.4 before 8.4(1.10), and 8.5 before 8.5(1.1) and Cisco Firewall Services Module (aka FWSM) 3.1 before 3.1(21), 3.2 before 3.2(22), 4.0 before 4.0(16), and 4.1 before 4.1(7) allow remote attackers to bypass authentication via a crafted TACACS+ reply, aka Bug IDs CSCto40365 and CSCto74274.

The Real-Time Information Server (RIS) Data Collector service in Cisco Unified Communications Manager (CUCM) 5.x before 5.1(3) and 6.x before 6.1(1) allows remote attackers to bypass authentication, and obtain cluster configuration information and statistics, via a direct TCP connection to the service port, aka Bug ID CSCsj90843.

The ios-authproxy implementation in Cisco IOS before 15.1(1)SY3 allows remote attackers to cause a denial of service (webauth and HTTP service outage) via vectors that trigger incorrectly terminated HTTP sessions, aka Bug ID CSCtz99447.

SNMPv3 HMAC verification in (1) Net-SNMP 5.2.x before 5.2.4.1, 5.3.x before 5.3.2.1, and 5.4.x before 5.4.1.1; (2) UCD-SNMP; (3) eCos; (4) Juniper Session and Resource Control (SRC) C-series 1.0.0 through 2.0.0; (5) NetApp (aka Network Appliance) Data ONTAP 7.3RC1 and 7.3RC2; (6) SNMP Research before 16.2; (7) multiple Cisco IOS, CatOS, ACE, and Nexus products; (8) Ingate Firewall 3.1.0 and later and SIParator 3.1.0 and later; (9) HP OpenView SNMP Emanate Master Agent 15.x; and possibly other products relies on the client to specify the HMAC length, which makes it easier for remote attackers to bypass SNMP authentication via a length value of 1, which only checks the first byte.

A vulnerability in the web console of the Cisco Cloud Services Platform (CSP) 2100 could allow an authenticated, remote attacker to interact maliciously with the services or virtual machines (VMs) operating remotely on an affected CSP device. The vulnerability is due to weaknesses in the generation of certain authentication mechanisms in the URL of the web console. An attacker could exploit this vulnerability by browsing to one of the hosted VMs' URLs in Cisco CSP and viewing specific patterns that control the web application's mechanisms for authentication control. An exploit could allow the attacker to access a specific VM on the CSP, which causes a complete loss of the system's confidentiality, integrity, and availability. This vulnerability affects Cisco Cloud Services Platform (CSP) 2100 running software release 2.1.0, 2.1.1, 2.1.2, 2.2.0, 2.2.1, or 2.2.2. Cisco Bug IDs: CSCve64690.

Unspecified vulnerability in the SSH server in (1) Cisco Service Control Engine (SCE) 3.0.x before 3.0.7 and 3.1.x before 3.1.0, and (2) Icon Labs Iconfidant SSH before 2.3.8, allows remote attackers to cause a denial of service (management interface outage) via SSH traffic that occurs during management operations and triggers "illegal I/O operations," aka Bug ID CSCsh49563.

Multiple vulnerabilities in Cisco BroadWorks CommPilot Application Software could allow an authenticated, remote attacker to delete arbitrary user accounts or gain elevated privileges on an affected system.

Cisco IOS 12.2E, 12.2F, and 12.2S places a "no login" line into the VTY configuration when an administrator makes certain changes to a (1) VTY/AUX or (2) CONSOLE setting on a device without AAA enabled, which allows remote attackers to bypass authentication and obtain a terminal session, a different vulnerability than CVE-1999-0293 and CVE-2005-2105.

Cisco Trust Agent (CTA) before 2.1.104.0, when running on MacOS X, allows attackers with physical access to bypass authentication and modify System Preferences, including passwords, by invoking the Apple Menu when the Access Control Server (ACS) produces a user notification message after posture validation.

The Cisco Unified IP Conference Station 7935 3.2(15) and earlier, and Station 7936 3.3(12) and earlier does not properly handle administrator HTTP sessions, which allows remote attackers to bypass authentication controls via a direct URL request to the administrative HTTP interface for a limited time

A vulnerability in the TCP Intercept functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Access Control Policies (including Geolocation) and Service Polices on an affected system. The vulnerability exists because TCP Intercept is invoked when the embryonic connection limit is reached, which can cause the underlying detection engine to process the packet incorrectly. An attacker could exploit this vulnerability by sending a crafted stream of traffic that matches a policy on which TCP Intercept is configured. A successful exploit could allow the attacker to match on an incorrect policy, which could allow the traffic to be forwarded when it should be dropped. In addition, the traffic could incorrectly be dropped.

Cisco Adaptive Security Appliances (ASA) 5500 series devices with software 7.2 through 8.4 do not properly perform proxy authentication during attempts to cut through a firewall, which allows remote attackers to obtain sensitive information via a connection attempt, aka Bug ID CSCtx42746.

A vulnerability in the dynamic access control list (ACL) feature of Cisco IOS XE Software running on Cisco Catalyst 4000 Series Switches could allow an unauthenticated, adjacent attacker to cause dynamic ACL assignment to fail and the port to fail open. This could allow the attacker to pass traffic to the default VLAN of the affected port. The vulnerability is due to an uncaught error condition that may occur during the reassignment of the auth-default-ACL dynamic ACL to a switch port after 802.1x authentication fails. A successful exploit of this issue could allow a physically adjacent attacker to bypass 802.1x authentication and cause the affected port to fail open, allowing the attacker to pass traffic to the default VLAN of the affected switch port. Cisco Bug IDs: CSCvc72751.

Cisco Firewall Services Module (aka FWSM) 3.1 before 3.1(21), 3.2 before 3.2(22), 4.0 before 4.0(16), and 4.1 before 4.1(7), when certain authentication configurations are used, allows remote attackers to cause a denial of service (module crash) by making many authentication requests for network access, aka Bug ID CSCtn15697.

Multiple vulnerabilities exist in the web-based management interface of Cisco Small Business RV Series Routers. A remote attacker could execute arbitrary commands or bypass authentication and upload files on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.