Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-09T00:00:00 openssl: Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-770

Issue summary: Remote peer may exhaust heap memory of the QUIC server or client by flooding it with packets containing PATH_CHALLENGE frames. Impact summary: A malicious remote peer can cause an unbounded memory allocation which can lead to an abnormal termination of the application acting as a QUIC client or server and a Denial of Service. A remote peer may exhaust heap memory by flooding the local QUIC stack with PATH_CHALLENGE frames. The local QUIC stack allocates a PATH_RESPONSE frame for every PATH_CHALLENGE it receives. The allocated PATH_RESPONSE frame gets freed only when the remote peer acknowledges reception of the PATH_RESPONSE frame which will not be done by a malicious peer. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue. The QUIC stack is outside of OpenSSL FIPS module boundary.

A flaw was found in OpenSSL's QUIC PATH_CHALLENGE handler. A remote attacker can exploit this vulnerability by flooding a QUIC client or server with specially crafted PATH_CHALLENGE frames. This leads to unbounded memory allocation within the local QUIC stack, as the system continuously allocates PATH_RESPONSE frames without them being acknowledged. The primary consequence is a Denial of Service (DoS), causing the affected application to terminate abnormally due to memory exhaustion.

A Moderate severity flaw exists in the QUIC PATH_CHALLENGE handler, allowing a remote attacker to exhaust heap memory of a QUIC client or server. By flooding the local QUIC stack with PATH_CHALLENGE frames, a malicious peer can trigger unbounded memory allocation, leading to a denial of service for applications utilizing the vulnerable QUIC implementation. To mitigate this vulnerability, apply UDP rate limiting at your network edge to throttle malicious traffic. If QUIC is not strictly required, disable the listener entirely and configure your application to use standard TLS over TCP. Additionally, enforce strict process memory limits using cgroups to prevent host-wide memory exhaustion during an attack. Red Hat Enterprise Linux 10 2026-06-11T00:00:00Z RHSA-2026:25237 openssl-1:3.5.5-4.el10_2 Red Hat Enterprise Linux 9 2026-06-11T00:00:00Z RHSA-2026:25239 openssl-1:3.5.5-4.el9_8 Red Hat Enterprise Linux 9 2026-06-11T00:00:00Z RHSA-2026:25239 openssl-1:3.5.5-4.el9_8 Cost Management 4 2026-07-15T00:00:00Z RHSA-2026:39981 costmanagement/costmanagement-metrics-rhel9-operator:1783539156 Red Hat Discovery 2 2026-06-24T00:00:00Z RHSA-2026:29197 discovery/discovery-server-rhel9:1782159791 Red Hat Discovery 2 2026-06-24T00:00:00Z RHSA-2026:29197 discovery/discovery-ui-rhel9:1782166952 Red Hat Insights proxy 1.5 2026-07-01T00:00:00Z RHSA-2026:34102 insights-proxy/insights-proxy-container-rhel9:1782890503 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/cds-rhel9:1781525684 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/haproxy-rhel9:1781525671 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/installer-rhel9:1781525693 Red Hat Update Infrastructure 5 2026-06-16T00:00:00Z RHSA-2026:26319 rhui5/rhua-rhel9:1781525739 Red Hat Update Infrastructure 5 2026-08-24T00:00:00Z RHSA-2026:58981 rhui5/cds-kubernetes-tp-rhel9:1787241211 Red Hat Update Infrastructure 5 2026-08-24T00:00:00Z RHSA-2026:58981 rhui5/installer-tp-rhel9:1787135742 Red Hat Update Infrastructure 5 2026-08-24T00:00:00Z RHSA-2026:58981 rhui5/rhua-tp-rhel9:1787241260 Red Hat Enterprise Linux 10 Not affected edk2 Red Hat Enterprise Linux 10 Not affected shim Red Hat Enterprise Linux 10 Not affected shim-unsigned-aarch64 Red Hat Enterprise Linux 10 Not affected shim-unsigned-x64 Red Hat Enterprise Linux 6 Not affected openssl Red Hat Enterprise Linux 7 Not affected ovmf Red Hat Enterprise Linux 8 Not affected compat-openssl10 Red Hat Enterprise Linux 8 Not affected edk2 Red Hat Enterprise Linux 8 Not affected mingw-openssl Red Hat Enterprise Linux 8 Not affected openssl Red Hat Enterprise Linux 8 Not affected shim Red Hat Enterprise Linux 8 Not affected shim-unsigned-x64 Red Hat Enterprise Linux 9 Not affected compat-openssl11 Red Hat Enterprise Linux 9 Not affected edk2 Red Hat Enterprise Linux 9 Not affected shim Red Hat Enterprise Linux 9 Not affected shim-unsigned-aarch64 Red Hat Enterprise Linux 9 Not affected shim-unsigned-x64 Red Hat JBoss Core Services Not affected jbcs-httpd24-openssl Red Hat JBoss Core Services Not affected jbcs-openssl-win6-x86_64.zip Red Hat JBoss Web Server 6 Not affected jws-optional-native-components-win6-x86_64.zip Red Hat JBoss Web Server 7 Not affected jws-optional-native-components-win6-x86_64.zip Red Hat OpenShift Container Platform 4 Affected openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 4 Affected openshift/ose-rhel-coreos-9 https://www.cve.org/CVERecord?id=CVE-2026-34183 https://nvd.nist.gov/vuln/detail/CVE-2026-34183