{"id":"CVE-2026-31835","summary":"Vaultwarden WebAuthn credential metadata tampered before signature verification","details":"Vaultwarden is a Bitwarden-compatible server written in Rust. In versions 1.35.4 and earlier, the WebAuthn authentication flow in `validate_webauthn_login()` updates persistent credential metadata (1backup_eligible1 and 1backup_state flags1) based on unverified `authenticatorData` before signature validation is performed. An attacker who knows a user's password but cannot produce a valid WebAuthn signature can permanently modify the stored backup flags for that user's credential. If signature verification fails, the database update is not rolled back. This can result in a persistent denial of service of WebAuthn two-factor authentication for affected credentials. This issue has been fixed in version 1.35.5.","aliases":["GHSA-x7g7-cgx5-jhx2"],"modified":"2026-08-12T03:51:33.410408804Z","published":"2026-05-05T18:51:35.457Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-345"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31835.json"},"references":[{"type":"WEB","url":"https://github.com/dani-garcia/vaultwarden/releases/tag/1.35.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31835.json"},{"type":"ADVISORY","url":"https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-x7g7-cgx5-jhx2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31835"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/dani-garcia/vaultwarden","events":[{"introduced":"0"},{"fixed":"39954af96aff8eb70eb4d26969abc1458bc4804f"}],"database_specific":{"cpe":"cpe:2.3:a:dani-garcia:vaultwarden:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.35.5"}],"source":["AFFECTED_FIELD","CPE_RANGE","REFERENCES"]}}],"versions":["1.35.4","1.35.3","1.35.2","1.35.1","1.35.0","1.34.3","1.34.2","1.34.1","1.34.0","1.33.2","1.33.1","1.33.0","1.32.7","1.32.6","1.32.5","1.32.4","1.32.3","1.32.2","1.32.1","1.32.0","1.31.0","1.30.5","1.30.4","1.30.3","1.30.2","1.30.1","1.30.0","1.29.2","1.29.1","1.29.0","1.28.1","1.28.0","1.27.0","1.26.0","1.25.2","1.25.1","1.25.0","1.24.0","1.23.1","1.23.0","1.22.2","1.22.1","1.22.0","1.21.0","1.20.0","1.19.0","1.18.0","1.17.0","1.16.3","1.16.2","1.16.1","1.16.0","1.15.1","1.15.0","1.14.2","1.14.1","1.14","1.13.1","1.13.0","1.12.0","1.11.0","1.10.0","1.9.1","1.9.0","1.8.0","1.7.0","1.6.1","1.6.0","1.5.0","1.4.0","1.3.0","1.2.0","1.1.0","1.0.0","0.13.0","0.12.0","0.11.0","0.10.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31835.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}]}