Logo
-

Byte Open Security

(ByteOS Network)

Log In

Sign Up

ByteOS

Security
Vulnerability Details
Registries
Custom Views
Weaknesses
Attack Patterns
Filters & Tools
Vulnerability Details :

CVE-2026-27855

Summary
Assigner-OX
Assigner Org ID-8ce71d90-2354-404b-a86e-bec2cc4e6981
Published At-27 Mar, 2026 | 08:10
Updated At-27 Mar, 2026 | 19:39
Rejected At-
Credits

Dovecot OTP authentication is vulnerable to replay attack under specific conditions. If auth cache is enabled, and username is altered in passdb, then OTP credentials can be cached so that same OTP reply is valid. An attacker able to observe an OTP exchange is able to log in as the user. If authentication happens over unsecure connection, switch to SCRAM protocol. Alternatively ensure the communcations are secured, and if possible switch to OAUTH2 or SCRAM. No publicly available exploits are known.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
â–¼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:OX
Assigner Org ID:8ce71d90-2354-404b-a86e-bec2cc4e6981
Published At:27 Mar, 2026 | 08:10
Updated At:27 Mar, 2026 | 19:39
Rejected At:
â–¼CVE Numbering Authority (CNA)

Dovecot OTP authentication is vulnerable to replay attack under specific conditions. If auth cache is enabled, and username is altered in passdb, then OTP credentials can be cached so that same OTP reply is valid. An attacker able to observe an OTP exchange is able to log in as the user. If authentication happens over unsecure connection, switch to SCRAM protocol. Alternatively ensure the communcations are secured, and if possible switch to OAUTH2 or SCRAM. No publicly available exploits are known.

Affected Products
Vendor
Open-Xchange AGOpen-Xchange GmbH
Product
OX Dovecot Pro
Modules
  • core
Default Status
unaffected
Versions
Affected
  • From 0 through 2.3.0 (semver)
Problem Types
TypeCWE IDDescription
cweCWE-294Authentication Bypass by Capture-replay
Type: cwe
CWE ID: CWE-294
Description: Authentication Bypass by Capture-replay
Metrics
VersionBase scoreBase severityVector
3.16.8MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Version: 3.1
Base score: 6.8
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json
vendor-advisory
Hyperlink: https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json
Resource:
vendor-advisory
â–¼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
Information is not available yet
â–¼National Vulnerability Database (NVD)
nvd.nist.gov
Source:security@open-xchange.com
Published At:27 Mar, 2026 | 09:16
Updated At:29 Apr, 2026 | 19:23

Dovecot OTP authentication is vulnerable to replay attack under specific conditions. If auth cache is enabled, and username is altered in passdb, then OTP credentials can be cached so that same OTP reply is valid. An attacker able to observe an OTP exchange is able to log in as the user. If authentication happens over unsecure connection, switch to SCRAM protocol. Alternatively ensure the communcations are secured, and if possible switch to OAUTH2 or SCRAM. No publicly available exploits are known.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary3.16.8MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Primary3.15.9MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Type: Secondary
Version: 3.1
Base score: 6.8
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Type: Primary
Version: 3.1
Base score: 5.9
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CPE Matches

Dovecot
dovecot
>>dovecot>>Versions before 2.4.3(exclusive)
cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:*
Open-Xchange AG
open-xchange
>>dovecot>>Versions up to 2.3.0(inclusive)
cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:*
Weaknesses
CWE IDTypeSource
CWE-294Secondarysecurity@open-xchange.com
CWE ID: CWE-294
Type: Secondary
Source: security@open-xchange.com
Evaluator Description

Evaluator Impact

Evaluator Solution

Vendor Statements

References
HyperlinkSourceResource
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.jsonsecurity@open-xchange.com
Vendor Advisory
Hyperlink: https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json
Source: security@open-xchange.com
Resource:
Vendor Advisory

Change History

0
Information is not available yet

Similar CVEs

6Records found

CVE-2026-27856
Matching Score-8
Assigner-Open-Xchange
ShareView Details
Matching Score-8
Assigner-Open-Xchange
CVSS Score-7.4||HIGH
EPSS-0.02% / 3.84%
||
7 Day CHG~0.00%
Published-27 Mar, 2026 | 08:10
Updated-29 Apr, 2026 | 19:25
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available

Doveadm credentials are verified using direct comparison which is susceptible to timing oracle attack. An attacker can use this to determine the configured credentials. Figuring out the credential will lead into full access to the affected component. Limit access to the doveadm http service port, install fixed version. No publicly available exploits are known.

Action-Not Available
Vendor-Open-Xchange AGDovecot
Product-dovecotOX Dovecot Pro
CWE ID-CWE-287
Improper Authentication
CVE-2023-33621
Matching Score-4
Assigner-MITRE Corporation
ShareView Details
Matching Score-4
Assigner-MITRE Corporation
CVSS Score-5.9||MEDIUM
EPSS-0.07% / 20.07%
||
7 Day CHG~0.00%
Published-13 Jun, 2023 | 00:00
Updated-03 Jan, 2025 | 02:24
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available

GL.iNET GL-AR750S-Ext firmware v3.215 inserts the admin authentication token into a GET request when the OpenVPN Server config file is downloaded. The token is then left in the browser history or access logs, potentially allowing attackers to bypass authentication via session replay.

Action-Not Available
Vendor-gl-inetn/a
Product-gl-ar750sgl-ar750s_firmwaren/a
CWE ID-CWE-294
Authentication Bypass by Capture-replay
CVE-2025-35061
Matching Score-4
Assigner-Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government
ShareView Details
Matching Score-4
Assigner-Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government
CVSS Score-8.2||HIGH
EPSS-0.05% / 16.83%
||
7 Day CHG~0.00%
Published-09 Oct, 2025 | 20:22
Updated-22 Oct, 2025 | 16:51
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
Newforma Info Exchange (NIX) forced NTLMv2 authentication via /NPCSRemoteWeb/LegacyIntegrationServices.asmx

Newforma Info Exchange (NIX) '/NPCSRemoteWeb/LegacyIntegrationServices.asmx' allows a remote, unauthenticated attacker to cause NIX to make an SMB connection to an attacker-controlled system. The attacker can capture the NTLMv2 hash of the user-configured NIX service account.

Action-Not Available
Vendor-newformaNewforma
Product-project_centerProject Center
CWE ID-CWE-294
Authentication Bypass by Capture-replay
CVE-2021-22267
Matching Score-4
Assigner-MITRE Corporation
ShareView Details
Matching Score-4
Assigner-MITRE Corporation
CVSS Score-5.9||MEDIUM
EPSS-0.33% / 55.97%
||
7 Day CHG~0.00%
Published-09 Feb, 2021 | 18:23
Updated-03 Aug, 2024 | 18:37
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available

Idelji Web ViewPoint Suite, as used in conjunction with HPE NonStop, allows a remote replay attack for T0320L01^ABP through T0320L01^ABZ, T0952L01^AAH through T0952L01^AAR, T0986L01 through T0986L01^AAF, T0665L01^AAP, and T0662L01^AAP (L) and T0320H01^ABO through T0320H01^ABY, T0952H01^AAG through T0952H01^AAQ, T0986H01 through T0986H01^AAE, T0665H01^AAO, and T0662H01^AAO (J and H).

Action-Not Available
Vendor-n/aHewlett Packard Enterprise (HPE)
Product-web_viewpointnonstopn/a
CWE ID-CWE-294
Authentication Bypass by Capture-replay
CVE-2013-1351
Matching Score-4
Assigner-MITRE Corporation
ShareView Details
Matching Score-4
Assigner-MITRE Corporation
CVSS Score-5.9||MEDIUM
EPSS-0.84% / 74.90%
||
7 Day CHG~0.00%
Published-30 Jan, 2020 | 13:20
Updated-06 Aug, 2024 | 14:57
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available

Verax NMS prior to 2.10 allows authentication via the encrypted password without knowing the cleartext password.

Action-Not Available
Vendor-veraxsystemsn/a
Product-network_management_systemn/a
CWE ID-CWE-294
Authentication Bypass by Capture-replay
CVE-2025-35058
Matching Score-4
Assigner-Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government
ShareView Details
Matching Score-4
Assigner-Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government
CVSS Score-8.2||HIGH
EPSS-0.05% / 16.83%
||
7 Day CHG~0.00%
Published-09 Oct, 2025 | 20:21
Updated-22 Oct, 2025 | 16:51
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
Newforma Info Exchange (NIX) forced NTLMv2 authentication via /UserWeb/Common/MarkupServices.ashx

Newforma Info Exchange (NIX) '/UserWeb/Common/MarkupServices.ashx' allows a remote, unauthenticated attacker to cause NIX to make an SMB connection to an attacker-controlled system. The attacker can capture the NTLMv2 hash of the customer-configured NIX service account.

Action-Not Available
Vendor-newformaNewforma
Product-project_centerProject Center
CWE ID-CWE-294
Authentication Bypass by Capture-replay
Details not found