Vulnerability in nghttp2 (CVE-2026-27135)
Summary
Vulnerability in nghttp2 (CVE-2026-27135). Risk of unauthorized operations or information disclosure. Exploitable via nghttp2_session_terminate_session.
Original description
The description as published by the source.
nghttp2 is an implementation of the Hypertext Transfer Protocol version 2 in C. Prior to version 1.68.1, the nghttp2 library stops reading the incoming data when user facing public API nghttp2_session_terminate_session or nghttp2_session_terminate_session2 is called by the application. They might be called internally by the library when it detects the situation that is subject to connection error. Due to the missing internal state validation, the library keeps reading the rest of the data after one of those APIs is called. Then receiving a malformed frame that causes FRAME_SIZE_ERROR causes assertion failure. nghttp2 v1.68.1 adds missing state validation to avoid assertion failure. No known workarounds are available.
Source: NIST National Vulnerability Database NVD
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-2026-27135 has been found in nghttp2.
Attackers can target a specific entry point like nghttp2_session_terminate_session over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "nghttp2 CVE-2026-27135" on the vendor's site.
CVE-2026-27135 (nghttp2) — CWE-617 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: nghttp2_session_terminate_session / nghttp2_session_terminate_session2
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-617) exists in nghttp2. Attackers reach the vulnerable code path via nghttp2_session_terminate_session without authentication.
Check the vendor advisory for the affected versions of nghttp2. Attack surface: nghttp2_session_terminate_session / nghttp2_session_terminate_session2.
Severity: High (CVSS 7.5/10). 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 'nghttp2' . 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 'nghttp2' . | 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
nghttp2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-2026-27135 nghttp2 Fixed in: 1.68.1
- Debian DEBIAN-CVE-2026-27135 nghttp2 Fixed in: 1.43.0-1+deb11u3
- Ubuntu UBUNTU-CVE-2026-27135 nghttp2 Fixed in: 1.7.1-1ubuntu0.1~esm3
References
- advisory openwall.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- web lists.debian.org
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
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- web bugzilla.redhat.com
- web security.access.redhat.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com