# CVE-2026-75805: NULL Pointer Dereference in CMP Client Revocation Response Handling CVE-2026-75805 is fixed in 15 products on 1 platform, first by libssl3t64 3.5.5-1ubuntu3.6, released September 28, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-75805 - Priority: Routine - CVSS: 5.3 (Moderate) - EPSS: 0.0032 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 28, 2026 - Weakness: NULL Pointer Dereference - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-75805 ## Description Issue summary: A CMP client that requests certificate revocation on the basis of a PKCS#10 CSR may dereference a NULL pointer and terminate abnormally when processing a crafted revocation response. Impact summary: The NULL pointer dereference happens on a read which leads to a crash and a Denial of Service for the affected client application. CWE: CWE-476: NULL-pointer dereference Description: A CMP client revoking a certificate has to tell the server which certificate to revoke, and may do so by supplying a PKCS#10 CSR instead of the certificate itself or its issuer name and serial number. This is 'openssl cmp -cmd rr -csr ' on the command line, or OSSL_CMP_exec_RR_ses() with the certificate supplied via OSSL_CMP_CTX_set1_p10CSR() through the API. A CSR does not contain the issuer name and serial number of the certificate, so the client does not send them. A server may optionally name the certificate it revoked in its response, and the client then compares that name against what it sent. Having sent neither an issuer name nor a serial number, it has nothing to compare against, and a server returning a specially crafted name causes the client to read from a NULL pointer and crash. The revocation response is checked for valid message protection before the affected code is reached, so an attacker must be a malicious or compromised CMP server, or a man-in-the-middle in possession of the secret used for message protection. Clients that identify the certificate to be revoked by a certificate or by issuer and serial number rather than by a PKCS#10 CSR are not affected. FIPS impact: no No FIPS modules are affected by this issue, as the CMP protocol implementation is outside the OpenSSL FIPS module boundary. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | libssl3 Ubuntu 22.04.1 LTS (jammy) | 3.0.2-0ubuntu1.30 | [libssl3 3.0.2-0ubuntu1.30](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libssl3-3.0.2-0ubuntu1.30.md) | Sep 30, 2026 | | Linux | libssl3t64 Ubuntu 24.04.5 LTS (noble) | 3.0.13-0ubuntu3.16 | [libssl3t64 3.0.13-0ubuntu3.16](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libssl3t64-3.0.13-0ubuntu3.16.md) | Sep 30, 2026 | | Linux | libssl3t64 Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3.6 | [libssl3t64 3.5.5-1ubuntu3.6](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libssl3t64-3.5.5-1ubuntu3.6.md) | Sep 28, 2026 | | Linux | openssl Debian 12.15 (bookworm) | 3.0.22-1~deb12u2 | [DEBIAN-CVE-2026-75805](https://patchblox.com/security/data/fix/linux/debian-cve-2026-75805.md) | Sep 30, 2026 | | Linux | openssl Debian 13.5 (trixie) | 3.5.7-1~deb13u3 | [DEBIAN-CVE-2026-75805](https://patchblox.com/security/data/fix/linux/debian-cve-2026-75805.md) | Sep 30, 2026 | | Linux | openssl Debian 14 | 3.6.5-1 | [DEBIAN-CVE-2026-75805](https://patchblox.com/security/data/fix/linux/debian-cve-2026-75805.md) | Sep 30, 2026 | | Linux | openssl Ubuntu 22.04.1 LTS (jammy) | 3.0.2-0ubuntu1.30 | [openssl 3.0.2-0ubuntu1.30](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-openssl-3.0.2-0ubuntu1.30.md) | Sep 30, 2026 | | Linux | openssl Ubuntu 24.04.5 LTS (noble) | 3.0.13-0ubuntu3.16 | [openssl 3.0.13-0ubuntu3.16](https://patchblox.com/security/data/fix/linux/ubuntu-noble-openssl-3.0.13-0ubuntu3.16.md) | Sep 30, 2026 | | Linux | openssl Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3.6 | [openssl 3.5.5-1ubuntu3.6](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-openssl-3.5.5-1ubuntu3.6.md) | Sep 28, 2026 | | Linux | openssl amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-3 opensuse-leap 16.0 | 3.5.0-160000.11.1 | [OPENSUSE-SU-2026:22102-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22102-1.md) | Nov 7, 2026 | | Linux | openssl-3 sles 15.6 | 3.1.4-150600.5.67.1 | [SUSE-SU-2026:4419-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4419-1.md) | Oct 2, 2026 | | Linux | openssl-3 sles 15.7 | 3.5.0-150700.5.53.2 | [SUSE-SU-2026:4414-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4414-1.md) | Oct 2, 2026 | | Linux | openssl-3 sles 16.0 | 3.5.0-160000.11.1 | [SUSE-SU-2026:24245-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24245-1.md) | Nov 7, 2026 | | Linux | openssl-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-debugsource amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-devel amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-fips-provider-latest amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-fips-provider-latest-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-libs amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-libs-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-perl amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-provider-legacy Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3.6 | [openssl-provider-legacy 3.5.5-1ubuntu3.6](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-openssl-provider-legacy-3.5.5-1ubuntu3.6.md) | Sep 28, 2026 | | Linux | openssl-snapsafe-libs amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | | Linux | openssl-snapsafe-libs-debuginfo amzn 2023 | 1:3.5.8-1.amzn2023.0.3 | [ALAS2023-2026-3204](https://patchblox.com/security/data/fix/linux/alas2023-2026-3204.md) | Nov 7, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.