Vulnerability in oauth2-proxy (CVE-2026-34457)
Summary
Vulnerability in oauth2-proxy (CVE-2026-34457). Confidential information can be exposed externally. Mitigation: upgrade to 7.15.2 or later.
Original description
The description as published by the source.
OAuth2 Proxy's Health Check User-Agent Matching Bypasses Authentication in auth_request Mode in github.com/oauth2-proxy/oauth2-proxy
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-2026-34457 has been found in oauth2-proxy.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade oauth2-proxy to 7.15.2 or later.
If unsure, ask your IT team or search "oauth2-proxy CVE-2026-34457" on the vendor's site.
CVE-2026-34457 (oauth2-proxy) — CWE-290 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 7.15.2 — 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-290) exists in oauth2-proxy.
Check the vendor advisory for the affected versions of oauth2-proxy.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 7.15.2.
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 'oauth2-proxy' . 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 'oauth2-proxy' . | 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
oauth2-proxy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 oauth2-proxy to 7.15.2ステージング環境で 7.15.2 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
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- web github.com