Vulnerability in golang.org/x/crypto (CVE-2026-39831)
Summary
Vulnerability in golang.org/x/crypto (CVE-2026-39831). Confidential information can be exposed externally. Mitigation: upgrade to 0.52.0 or later.
Original description
The description as published by the source.
The Verify() method for FIDO/U2F security key types (sk-ecdsa-sha2-nistp256@openssh.com, sk-ssh-ed25519@openssh.com) did not check the User Presence flag. Signatures generated without physical touch were accepted, allowing unattended use of a hardware security key. To restore the previous behavior, return a "no-touch-required" extension in Permissions.Extensions from PublicKeyCallback.
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-2026-39831 has been found in golang.org/x/crypto.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade golang.org/x/crypto to 0.52.0 or later.
If unsure, ask your IT team or search "golang.org/x/crypto CVE-2026-39831" on the vendor's site.
CVE-2026-39831 (golang.org/x/crypto) — CWE-862 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 0.52.0 — apply immediately
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-862) exists in golang.org/x/crypto.
Check the vendor advisory for the affected versions of golang.org/x/crypto.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 0.52.0.
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 'golang.org/x/crypto' . 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
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1Identify exposure identify
grep -r 'golang.org/x/crypto' . | 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
golang.org/x/cryptoを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade golang.org/x/crypto to 0.52.0ステージング環境で 0.52.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-39831 buildah
- Debian DEBIAN-CVE-2026-39831 golang-go.crypto
- Ubuntu UBUNTU-CVE-2026-39831 golang-go.crypto
References
- advisory nvd.nist.gov
- package cs.opensource.google
- web go.dev
- web go.dev
- web groups.google.com
- web pkg.go.dev
- web github.com