Vulnerability in tls (CVE-2026-45388)
Summary
Vulnerability in tls (CVE-2026-45388). Confidential information can be exposed externally. Mitigation: upgrade to 2.1.0, 6a12247b3fbd747972ad2d35b74d9a89f6404952 or later.
Original description
The description as published by the source.
In OCaml-TLS before 2.1.0, the client implementation does insufficient checks of the certificate provided by the server, which allows impersonation with certificates that are not meant for server authentication (because of KeyUsage and ExtendedKeyUsage).
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
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-2026-45388 has been found in tls.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade tls to 2.1.0, 6a12247b3fbd747972ad2d35b74d9a89f6404952 or later.
If unsure, ask your IT team or search "tls CVE-2026-45388" on the vendor's site.
CVE-2026-45388 (tls) — CWE-295 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 2.1.0, 6a12247b3fbd747972ad2d35b74d9a89f6404952 — 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-295) exists in tls.
Check the vendor advisory for the affected versions of tls.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 2.1.0, 6a12247b3fbd747972ad2d35b74d9a89f6404952.
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 'tls' . 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 'tls' . | 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
tls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 tls to 2.1.0, 6a12247b3fbd747972ad2d35b74d9a89f6404952ステージング環境で 2.1.0, 6a12247b3fbd747972ad2d35b74d9a89f6404952 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
References
- web osv.dev
- web nvd.nist.gov
- web github.com