h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The QUIC stack (quicly), as used by H2O up to commit 43f86e5 (in version 2.3.0-beta and prior), is susceptible to a state exhaustion attack. When H2O is serving HTTP/3, a remote attacker can exploit this vulnerability to progressively increase the memory retained by the QUIC stack. This can eventually cause H2O to abort due to memory exhaustion. The vulnerability has been resolved in commit d67e81d03be12a9d53dc8271af6530f40164cd35. HTTP/1 and HTTP/2 are not affected by this vulnerability as they do not use QUIC. Administrators looking to mitigate this issue without upgrading can disable HTTP/3 support.

Impact Cloudflare quiche was discovered to be vulnerable to incorrect congestion window growth, which could cause it to send data at a rate faster than the path might actually support. An unauthenticated remote attacker can exploit the vulnerability by first completing a handshake and initiating a congestion-controlled data transfer towards itself. Then, it could manipulate the victim's congestion control state by sending ACK frames covering a large range of packet numbers (including packet numbers that had never been sent); see RFC 9000 Section 19.3. The victim could grow the congestion window beyond typical expectations and allow more bytes in flight than the path might really support. In extreme cases, the window might grow beyond the limit of the internal variable's type, leading to an overflow panic. Patches quiche 0.24.4 is the earliest version containing the fix for this issue.

CNCF Envoy through 1.13.0 may consume excessive amounts of memory when proxying HTTP/1.1 requests or responses with many small (i.e. 1 byte) chunks.

Very large headers can cause resource exhaustion when parsing message. The message-parser normally reads reasonably sized chunks of the message. However, when it feeds them to message-header-parser, it starts building up "full_value" buffer out of the smaller chunks. The full_value buffer has no size limit, so large headers can cause large memory usage. It doesn't matter whether it's a single long header line, or a single header split into multiple lines. This bug exists in all Dovecot versions. Incoming mails typically have some size limits set by MTA, so even largest possible header size may still fit into Dovecot's vsz_limit. So attackers probably can't DoS a victim user this way. A user could APPEND larger mails though, allowing them to DoS themselves (although maybe cause some memory issues for the backend in general). One can implement restrictions on headers on MTA component preceding Dovecot. No publicly available exploits are known.

Grackle is a GraphQL server written in functional Scala, built on the Typelevel stack. The GraphQL specification requires that GraphQL fragments must not form cycles, either directly or indirectly. Prior to Grackle version 0.18.0, that requirement wasn't checked, and queries with cyclic fragments would have been accepted for type checking and compilation. The attempted compilation of such fragments would result in a JVM `StackOverflowError` being thrown. Some knowledge of an applications GraphQL schema would be required to construct such a query, however no knowledge of any application-specific performance or other behavioural characteristics would be needed. Grackle uses the cats-parse library for parsing GraphQL queries. Prior to version 0.18.0, Grackle made use of the cats-parse `recursive` operator. However, `recursive` is not currently stack safe. `recursive` was used in three places in the parser: nested selection sets, nested input values (lists and objects), and nested list type declarations. Consequently, queries with deeply nested selection sets, input values or list types could be constructed which exploited this, causing a JVM `StackOverflowException` to be thrown during parsing. Because this happens very early in query processing, no specific knowledge of an applications GraphQL schema would be required to construct such a query. The possibility of small queries resulting in stack overflow is a potential denial of service vulnerability. This potentially affects all applications using Grackle which have untrusted users. Both stack overflow issues have been resolved in the v0.18.0 release of Grackle. As a workaround, users could interpose a sanitizing layer in between untrusted input and Grackle query processing.

In OpenDDS through 3.27, there is a segmentation fault for a DataWriter with a large value of resource_limits.max_samples. NOTE: the vendor's position is that the product is not designed to handle a max_samples value that is too large for the amount of memory on the system.

CoreDNS is a DNS server that chains plugins. In versions prior to 1.12.2, a Denial of Service (DoS) vulnerability exists in the CoreDNS DNS-over-QUIC (DoQ) server implementation. The server previously created a new goroutine for every incoming QUIC stream without imposing any limits on the number of concurrent streams or goroutines. A remote, unauthenticated attacker could open a large number of streams, leading to uncontrolled memory consumption and eventually causing an Out Of Memory (OOM) crash — especially in containerized or memory-constrained environments. The patch in version 1.12.2 introduces two key mitigation mechanisms: `max_streams`, which caps the number of concurrent QUIC streams per connection with a default value of `256`; and `worker_pool_size`, which Introduces a server-wide, bounded worker pool to process incoming streams with a default value of `1024`. This eliminates the 1:1 stream-to-goroutine model and ensures that CoreDNS remains resilient under high concurrency. Some workarounds are available for those who are unable to upgrade. Disable QUIC support by removing or commenting out the `quic://` block in the Corefile, use container runtime resource limits to detect and isolate excessive memory usage, and/or monitor QUIC connection patterns and alert on anomalies.

CiphertextHeader.java in Cryptacular 1.2.3, as used in Apereo CAS and other products, allows attackers to trigger excessive memory allocation during a decode operation, because the nonce array length associated with "new byte" may depend on untrusted input within the header of encoded data.

In Connect2id Nimbus JOSE+JWT before 9.37.2, an attacker can cause a denial of service (resource consumption) via a large JWE p2c header value (aka iteration count) for the PasswordBasedDecrypter (PBKDF2) component.

A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. This issue could allow a malicious user could to repeatedly send requests that exceed the max-header-size, causing a Denial of Service (DoS).

The package opcua from 0.0.0 are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.

The package org.eclipse.milo:sdk-server before 0.6.8 are vulnerable to Denial of Service (DoS) when bypassing the limitations for excessive memory consumption by sending multiple CloseSession requests with the deleteSubscription parameter equal to False.

HashiCorp Consul and Consul Enterprise up to 1.6.2 HTTP/RPC services allowed unbounded resource usage, and were susceptible to unauthenticated denial of service. Fixed in 1.6.3.

All versions of package opcua; all versions of package asyncua are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.

The package node-opcua before 2.74.0 are vulnerable to Denial of Service (DoS) by sending a specifically crafted OPC UA message with a special OPC UA NodeID, when the requested memory allocation exceeds the v8’s memory limit.

All versions of package asneg/opcuastack are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.

HashiCorp Nomad and Nomad Enterprise 1.0.17, 1.1.11, and 1.2.5 allow invalid HCL for the jobs parse endpoint, which may cause excessive CPU usage. Fixed in 1.0.18, 1.1.12, and 1.2.6.

In api.rb in Sidekiq before 5.2.10 and 6.4.0, there is no limit on the number of days when requesting stats for the graph. This overloads the system, affecting the Web UI, and makes it unavailable to users.

A Denial-of-Service (DoS) vulnerability was discovered in F-Secure Atlant whereby the fsicapd component used in certain F-Secure products while scanning larger packages/fuzzed files consume too much memory eventually can crash the scanning engine. The exploit can be triggered remotely by an attacker.

Pexip Infinity 27 before 28.0 allows remote attackers to trigger excessive resource consumption and termination because of registrar resource mishandling.

All versions of package freeopcua/freeopcua are vulnerable to Denial of Service (DoS) when bypassing the limitations for excessive memory consumption by sending multiple CloseSession requests with the deleteSubscription parameter equal to False.

js-libp2p is the official javascript Implementation of libp2p networking stack. Versions older than `v0.38.0` of js-libp2p are vulnerable to targeted resource exhaustion attacks. These attacks target libp2p’s connection, stream, peer, and memory management. An attacker can cause the allocation of large amounts of memory, ultimately leading to the process getting killed by the host’s operating system. While a connection manager tasked with keeping the number of connections within manageable limits has been part of js-libp2p, this component was designed to handle the regular churn of peers, not a targeted resource exhaustion attack. Users are advised to update their js-libp2p dependency to `v0.38.0` or greater. There are no known workarounds for this vulnerability.

libp2p-rust is the official rust language Implementation of the libp2p networking stack. In versions prior to 0.45.1 an attacker node can cause a victim node to allocate a large number of small memory chunks, which can ultimately lead to the victim’s process running out of memory and thus getting killed by its operating system. When executed continuously, this can lead to a denial of service attack, especially relevant on a larger scale when run against more than one node of a libp2p based network. Users are advised to upgrade to `libp2p` `v0.45.1` or above. Users unable to upgrade should reference the DoS Mitigation page for more information on how to incorporate mitigation strategies, monitor their application, and respond to attacks: https://docs.libp2p.io/reference/dos-mitigation/.

A malicious user may submit a specially-crafted complex payload that otherwise meets the default request size limit which results in excessive memory and CPU consumption of Vault. This may lead to a timeout in Vault’s auditing subroutine, potentially resulting in the Vault server to become unresponsive. This vulnerability, CVE-2025-6203, is fixed in Vault Community Edition 1.20.3 and Vault Enterprise 1.20.3, 1.19.9, 1.18.14, and 1.16.25.

In Spring Cloud Function versions prior to 3.2.6, it is possible for a user who directly interacts with framework provided lookup functionality to cause a denial-of-service condition due to the caching issue in the Function Catalog component of the framework.

An issue was discovered in Django 3.2 before 3.2.23, 4.1 before 4.1.13, and 4.2 before 4.2.7. The NFKC normalization is slow on Windows. As a consequence, django.contrib.auth.forms.UsernameField is subject to a potential DoS (denial of service) attack via certain inputs with a very large number of Unicode characters.

Helm is a tool for managing Charts, pre-configured Kubernetes resources. Versions prior to 3.10.3 are subject to Uncontrolled Resource Consumption, resulting in Denial of Service. Input to functions in the _strvals_ package can cause a stack overflow. In Go, a stack overflow cannot be recovered from. Applications that use functions from the _strvals_ package in the Helm SDK can have a Denial of Service attack when they use this package and it panics. This issue has been patched in 3.10.3. SDK users can validate strings supplied by users won't create large arrays causing significant memory usage before passing them to the _strvals_ functions.

The jose2go component before 1.6.0 for Go allows attackers to cause a denial of service (CPU consumption) via a large p2c (aka PBES2 Count) value.

Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 22.2.0, Twisted SSH client and server implement is able to accept an infinite amount of data for the peer's SSH version identifier. This ends up with a buffer using all the available memory. The attach is a simple as `nc -rv localhost 22 < /dev/zero`. A patch is available in version 22.2.0. There are currently no known workarounds.

A vulnerability in SonicOS CFS (Content filtering service) returns a large 403 forbidden HTTP response message to the source address when users try to access prohibited resource this allows an attacker to cause HTTP Denial of Service (DoS) attack

NVIDIA FLARE contains a vulnerability in the admin interface, where an un-authorized attacker can cause Allocation of Resources Without Limits or Throttling, which may lead to cause system unavailable.

An Allocation of Resources Without Limits or Throttling vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved allows unauthenticated network based attacker to cause a Denial of Service (DoS). On all Junos Evolved platforms hostbound protocols will be impacted by a high rate of specific hostbound traffic from ports on a PFE. Continued receipt of this amount of traffic will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS Evolved: 21.2 versions prior to 21.2R3-EVO; 21.3 versions prior to 21.3R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 21.2R1.

A Missing Authentication for Critical Function vulnerability in spacewalk-java of SUSE Manager Server 4.1, SUSE Manager Server 4.2 allows remote attackers to easily exhaust available disk resources leading to DoS. This issue affects: SUSE Manager Server 4.1 spacewalk-java versions prior to 4.1.46. SUSE Manager Server 4.2 spacewalk-java versions prior to 4.2.37.

Unsanitized input in the query parser in github.com/revel/revel before v1.0.0 allows remote attackers to cause resource exhaustion via memory allocation.

client_golang is the instrumentation library for Go applications in Prometheus, and the promhttp package in client_golang provides tooling around HTTP servers and clients. In client_golang prior to version 1.11.1, HTTP server is susceptible to a Denial of Service through unbounded cardinality, and potential memory exhaustion, when handling requests with non-standard HTTP methods. In order to be affected, an instrumented software must use any of `promhttp.InstrumentHandler*` middleware except `RequestsInFlight`; not filter any specific methods (e.g GET) before middleware; pass metric with `method` label name to our middleware; and not have any firewall/LB/proxy that filters away requests with unknown `method`. client_golang version 1.11.1 contains a patch for this issue. Several workarounds are available, including removing the `method` label name from counter/gauge used in the InstrumentHandler; turning off affected promhttp handlers; adding custom middleware before promhttp handler that will sanitize the request method given by Go http.Request; and using a reverse proxy or web application firewall, configured to only allow a limited set of methods.

A vulnerability in the Snort detection engine integration for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause unlimited memory consumption, which could lead to a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient memory management for certain Snort events. An attacker could exploit this vulnerability by sending a series of crafted IP packets that would generate specific Snort events on an affected device. A sustained attack could cause an out of memory condition on the affected device. A successful exploit could allow the attacker to interrupt all traffic flowing through the affected device. In some circumstances, the attacker may be able to cause the device to reload, resulting in a DoS condition.

Discourse is an open source platform for community discussion. In versions 3.1.0 through 3.1.2 of the `stable` branch and versions 3.1.0,beta6 through 3.2.0.beta2 of the `beta` and `tests-passed` branches, Redis memory can be depleted by crafting a site with an abnormally long favicon URL and drafting multiple posts which Onebox it. The issue is patched in version 3.1.3 of the `stable` branch and version 3.2.0.beta3 of the `beta` and `tests-passed` branches. There are no known workarounds.

A lack of rate limiting in pjActionAJaxSend in Availability Booking Calendar 5.0 allows attackers to cause resource exhaustion.

Pure-FTPd 1.0.48 allows remote attackers to prevent legitimate server use by making enough connections to exceed the connection limit.

OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. Prior to version 0.46.0, the grpc Unary Server Interceptor out of the box adds labels `net.peer.sock.addr` and `net.peer.sock.port` that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent. An attacker can easily flood the peer address and port for requests. Version 0.46.0 contains a fix for this issue. As a workaround to stop being affected, a view removing the attributes can be used. The other possibility is to disable grpc metrics instrumentation by passing `otelgrpc.WithMeterProvider` option with `noop.NewMeterProvider`.

An issue was discovered in the ws crate through 2020-09-25 for Rust. The outgoing buffer is not properly limited, leading to a remote memory-consumption attack.

pypdf is a free and open-source pure-python PDF library. Prior to version 6.0.0, an attacker can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access. This issue has been fixed in 6.0.0. If an update is not possible, a workaround involves including the fixed code from pypdf.filters.decompress into the existing filters file.

socket.io-parser before 3.4.1 allows attackers to cause a denial of service (memory consumption) via a large packet because a concatenation approach is used.

The package open62541/open62541 before 1.2.5, from 1.3-rc1 and before 1.3.1 are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.

jackson-databind 2.10.x through 2.12.x before 2.12.6 and 2.13.x before 2.13.1 allows attackers to cause a denial of service (2 GB transient heap usage per read) in uncommon situations involving JsonNode JDK serialization.

An issue was discovered in the ckb crate before 0.40.0 for Rust. Remote attackers may be able to conduct a 51% attack against the Nervos CKB blockchain by triggering an inability to allocate memory for the misbehavior HashMap.

This affects the package com.fasterxml.jackson.dataformat:jackson-dataformat-cbor from 0 and before 2.11.4, from 2.12.0-rc1 and before 2.12.1. Unchecked allocation of byte buffer can cause a java.lang.OutOfMemoryError exception.

Affected devices contain a vulnerability that allows an unauthenticated attacker to trigger a denial of service condition. The vulnerability can be triggered if a large amount of DCP reset packets are sent to the device.