← Back
CVE-2026-31789
critical
CVSS 9.8
Out-of-Bounds Write in openssl (CVE-2026-31789)
Summary
out-of-bounds write in openssl (CVE-2026-31789). Successful exploitation can lead to full system takeover.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-31789** has been found in openssl.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "openssl CVE-2026-31789" on the vendor's site.
CVE-2026-31789 (openssl) — CWE-787 / CVSS v3 9.8
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.
❓ What is the problem
**out-of-bounds write** (CWE-787) exists in openssl.
📍 Affected scope
openssl — .
🔥 Severity
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover
🔧 How to fix
Update to the patched release per vendor advisory.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
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 (7 steps)
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。
-
7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
References
- web https://github.com/openssl/openssl/commit/364f095b80601db632b0def6a33316967f863bde
- web https://github.com/openssl/openssl/commit/7a9087efd769f362ad9c0e30c7baaa6bbfa65ecf
- web https://github.com/openssl/openssl/commit/945b935ac66cc7f1a41f1b849c7c25adb5351f49
- web https://github.com/openssl/openssl/commit/a24216018e1ede8ff01a4ff5afff7dfbd443e2f9
- web https://github.com/openssl/openssl/commit/a91e537d16d74050dbde50bb0dfb1fe9930f0521
- web https://openssl-library.org/news/secadv/20260407.txt
- web https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- web https://nvd.nist.gov/vuln/detail/CVE-2026-31789
- web https://github.com/advisories/GHSA-j79m-9jxq-788r