Authentication Bypass in Logto (CVE-2026-55377)
Summary
Authentication bypass in Logto (CVE-2026-55377). Confidential information can be exposed externally.
Original description
The description as published by the source.
Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, Logto's Account Center step-up check accepted any active verification record that belonged to the current user and had isVerified === true. A WebAuthn registration verification record for binding a new passkey could be created and verified with only an existing Account API bearer token, then sent in the logto-verification-id header and treated as identityVerified=true by Account Center routes, allowing MFA factor management without proving possession of an existing password, identifier, or MFA factor. This issue is fixed in version 1.41.0.
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-2026-55377 has been found in Logto.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Logto CVE-2026-55377" on the vendor's site.
CVE-2026-55377 (Logto) — CWE-287 / CVSS v3 8.1
Attack vector: remote (network-reachable) / 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.
Authentication bypass (CWE-287) exists in Logto.
Check the vendor advisory for the affected versions of Logto.
Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.
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 'Logto' . 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 'Logto' . | 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
Logto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。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com
- patch github.com
- web github.com