# CVE-2026-63074: CMP Indefinite Cache Growth of ExtraCerts CVE-2026-63074 is fixed in 15 products on 1 platform, first by libssl3t64 3.5.5-1ubuntu3.4, released August 24, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-63074 - Priority: High - CVSS: 7.5 (Moderate) - EPSS: 0.0059 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 24, 2026 - Weakness: Allocation of Resources Without Limits or Throttling - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63074 ## Description Issue summary: The OpenSSL Certificate Management Protocol (CMP) caches additional certificates (extraCerts) sent in a CMP message, but never expunges them (for instance if they are invalid). If a server reuses an OSSL_CMP_CTX frequently, this cache of extraCerts may grow unboundedly, and a malicious client may flood a CMP server with requests driving this growth. Impact summary: Users utilizing a CMP server that reuses a single OSSL_CMP_CTX for the lifetime of a server process may observe unbounded memory growth in the event a malicious client repeatedly sends requests containing unique extra certificates, which may lead to OOM conditions. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: If a remote user sends CMP messages to a server with a list of extraCerts and the message is rejected, the extraCerts from the message remains in the server contexts untrusted certificate stack. This exposes servers with long lived ctx objects to Denial of Service attacks in which an attacker sends messages intending to be rejected with a large list of additional certificates repeatedly, forcing the server to store them indefinitely. The issue was fixed by removing the added extra certs if the message is rejected, using the same method as when the context is configured to not do caching at all. FIPS impact: no As the CMP code lives outside the FIPS module boundary, no FIPS modules are affected by this CVE. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | libssl3 Ubuntu 22.04.1 LTS (jammy) | 3.0.2-0ubuntu1.29 | [libssl3 3.0.2-0ubuntu1.29](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libssl3-3.0.2-0ubuntu1.29.md) | Aug 27, 2026 | | Linux | libssl3t64 Ubuntu 24.04.5 LTS (noble) | 3.0.13-0ubuntu3.15 | [libssl3t64 3.0.13-0ubuntu3.15](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libssl3t64-3.0.13-0ubuntu3.15.md) | Aug 27, 2026 | | Linux | libssl3t64 Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3.4 | [libssl3t64 3.5.5-1ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libssl3t64-3.5.5-1ubuntu3.4.md) | Aug 24, 2026 | | Linux | openssl Debian 12.15 (bookworm) | 3.0.22-1~deb12u1 | [DEBIAN-CVE-2026-63074](https://patchblox.com/security/data/fix/linux/debian-cve-2026-63074.md) | Aug 26, 2026 | | Linux | openssl Debian 13.5 (trixie) | 3.5.7-1~deb13u2 | [DEBIAN-CVE-2026-63074](https://patchblox.com/security/data/fix/linux/debian-cve-2026-63074.md) | Aug 26, 2026 | | Linux | openssl Debian 14 | 3.6.4-1 | [DEBIAN-CVE-2026-63074](https://patchblox.com/security/data/fix/linux/debian-cve-2026-63074.md) | Aug 26, 2026 | | Linux | openssl RHEL 10 | 3.5.8-1.el10_2 | [RHSA-2026:67154](https://patchblox.com/security/data/fix/linux/rhsa-2026-67154.md) | Sep 14, 2026 | | Linux | openssl RHEL 9 | 1:3.5.8-1.el9_8 | [RHSA-2026:67165](https://patchblox.com/security/data/fix/linux/rhsa-2026-67165.md) | Sep 19, 2026 | | Linux | openssl Ubuntu 22.04.1 LTS (jammy) | 3.0.2-0ubuntu1.29 | [openssl 3.0.2-0ubuntu1.29](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-openssl-3.0.2-0ubuntu1.29.md) | Aug 27, 2026 | | Linux | openssl Ubuntu 24.04.5 LTS (noble) | 3.0.13-0ubuntu3.15 | [openssl 3.0.13-0ubuntu3.15](https://patchblox.com/security/data/fix/linux/ubuntu-noble-openssl-3.0.13-0ubuntu3.15.md) | Aug 27, 2026 | | Linux | openssl Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3.4 | [openssl 3.5.5-1ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-openssl-3.5.5-1ubuntu3.4.md) | Aug 24, 2026 | | Linux | openssl almalinux 10 | 1:3.5.8-1.el10_2.alma.1 | [ALSA-2026:67154](https://patchblox.com/security/data/fix/linux/alsa-2026-67154.md) | Sep 14, 2026 | | Linux | openssl almalinux 9 | 1:3.5.8-1.el9_8 | [ALSA-2026:67165](https://patchblox.com/security/data/fix/linux/alsa-2026-67165.md) | Sep 14, 2026 | | Linux | openssl amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl ol 10 | 1:3.5.8-1.0.1.el10_2 | [ELSA-2026-67154-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67154-0.md) | Sep 14, 2026 | | Linux | openssl ol 9 | 1:3.5.8-1.0.1.el9_8 | [ELSA-2026-67165-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67165-0.md) | Sep 14, 2026 | | Linux | openssl rocky 10 | 1:3.5.8-1.el10_2 | [RLSA-2026:67154](https://patchblox.com/security/data/fix/linux/rlsa-2026-67154.md) | Sep 15, 2026 | | Linux | openssl rocky 9 | 1:3.5.8-1.el9_8 | [RLSA-2026:67165](https://patchblox.com/security/data/fix/linux/rlsa-2026-67165.md) | Sep 15, 2026 | | Linux | openssl-3 opensuse-leap 16.0 | 3.5.0-160000.10.1 | [OPENSUSE-SU-2026:21744-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21744-1.md) | Sep 2, 2026 | | Linux | openssl-3 sles 15.6 | 3.1.4-150600.5.64.1 | [SUSE-SU-2026:3866-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3866-1.md) | Aug 28, 2026 | | Linux | openssl-3 sles 15.7 | 3.5.0-150700.5.50.1 | [SUSE-SU-2026:4039-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4039-1.md) | Sep 7, 2026 | | Linux | openssl-3 sles 16.0 | 3.5.0-160000.10.1 | [SUSE-SU-2026:23609-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23609-1.md) | Sep 2, 2026 | | Linux | openssl-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-debugsource amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-devel RHEL 9 | 1:3.5.8-1.el9_8 | [RHSA-2026:67165](https://patchblox.com/security/data/fix/linux/rhsa-2026-67165.md) | Sep 19, 2026 | | Linux | openssl-devel almalinux 10 | 1:3.5.8-1.el10_2.alma.1 | [ALSA-2026:67154](https://patchblox.com/security/data/fix/linux/alsa-2026-67154.md) | Sep 14, 2026 | | Linux | openssl-devel almalinux 9 | 1:3.5.8-1.el9_8 | [ALSA-2026:67165](https://patchblox.com/security/data/fix/linux/alsa-2026-67165.md) | Sep 14, 2026 | | Linux | openssl-devel amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-devel ol 10 | 1:3.5.8-1.0.1.el10_2 | [ELSA-2026-67154-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67154-0.md) | Sep 14, 2026 | | Linux | openssl-devel ol 9 | 1:3.5.8-1.0.1.el9_8 | [ELSA-2026-67165-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67165-0.md) | Sep 14, 2026 | | Linux | openssl-fips-provider-latest amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-fips-provider-latest-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-libs RHEL 9 | 1:3.5.8-1.el9_8 | [RHSA-2026:67165](https://patchblox.com/security/data/fix/linux/rhsa-2026-67165.md) | Sep 19, 2026 | | Linux | openssl-libs almalinux 10 | 1:3.5.8-1.el10_2.alma.1 | [ALSA-2026:67154](https://patchblox.com/security/data/fix/linux/alsa-2026-67154.md) | Sep 14, 2026 | | Linux | openssl-libs almalinux 9 | 1:3.5.8-1.el9_8 | [ALSA-2026:67165](https://patchblox.com/security/data/fix/linux/alsa-2026-67165.md) | Sep 14, 2026 | | Linux | openssl-libs amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-libs ol 10 | 1:3.5.8-1.0.1.el10_2 | [ELSA-2026-67154-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67154-0.md) | Sep 14, 2026 | | Linux | openssl-libs ol 9 | 1:3.5.8-1.0.1.el9_8 | [ELSA-2026-67165-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67165-0.md) | Sep 14, 2026 | | Linux | openssl-libs-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-perl RHEL 9 | 1:3.5.8-1.el9_8 | [RHSA-2026:67165](https://patchblox.com/security/data/fix/linux/rhsa-2026-67165.md) | Sep 19, 2026 | | Linux | openssl-perl almalinux 10 | 1:3.5.8-1.el10_2.alma.1 | [ALSA-2026:67154](https://patchblox.com/security/data/fix/linux/alsa-2026-67154.md) | Sep 14, 2026 | | Linux | openssl-perl almalinux 9 | 1:3.5.8-1.el9_8 | [ALSA-2026:67165](https://patchblox.com/security/data/fix/linux/alsa-2026-67165.md) | Sep 14, 2026 | | Linux | openssl-perl amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-perl ol 10 | 1:3.5.8-1.0.1.el10_2 | [ELSA-2026-67154-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67154-0.md) | Sep 14, 2026 | | Linux | openssl-perl ol 9 | 1:3.5.8-1.0.1.el9_8 | [ELSA-2026-67165-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67165-0.md) | Sep 14, 2026 | | Linux | openssl-provider-legacy Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3.4 | [openssl-provider-legacy 3.5.5-1ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-openssl-provider-legacy-3.5.5-1ubuntu3.4.md) | Aug 24, 2026 | | Linux | openssl-snapsafe-libs amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | | Linux | openssl-snapsafe-libs-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.1 | [ALAS2023-2026-2136](https://patchblox.com/security/data/fix/linux/alas2023-2026-2136.md) | Sep 14, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. 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