Vulnerability in Openssl (CVE-2026-75805)
Summary
Vulnerability in Openssl (CVE-2026-75805). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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 revoke…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-75805 has been found in Openssl.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Openssl CVE-2026-75805" on the vendor's site.
CVE-2026-75805 (Openssl) — CWE-476 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-476) exists in Openssl.
Check the vendor advisory for the affected versions of Openssl.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Openssl' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Openssl' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Opensslを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Alpine Linux ALPINE-CVE-2026-75805 openssl Fixed in: 3.3.7-r2
References
- patch openssl-security@openssl.org
- patch openssl-security@openssl.org
- patch openssl-security@openssl.org
- patch openssl-security@openssl.org
- patch openssl-security@openssl.org
- web nvd.nist.gov
- web github.com