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CVE-2026-43911 Dani Garcia CVE debrief

CVE-2026-43911 is a medium-severity authentication/session-management issue in Vaultwarden. Prior to version 1.35.5, refresh tokens were not invalidated when a user’s security_stamp was rotated by certain security-sensitive actions, including password change, KDF change, key rotation, email change, org admin password reset, and emergency access takeover. As a result, an attacker who already obtained a refresh token could keep renewing session access even after the account owner took steps intended to secure the account. The published remediation is Vaultwarden 1.35.5.

Vendor
Dani Garcia
Product
Vaultwarden
CVSS
MEDIUM 6.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-11
Original CVE updated
2026-05-18
Advisory published
2026-05-11
Advisory updated
2026-05-18

Who should care

Vaultwarden administrators, identity and access management teams, and anyone responsible for user account recovery or credential-reset workflows. It is especially relevant where refresh tokens may have been exposed before an account was secured.

Technical summary

The issue is that refresh tokens were not invalidated when security-sensitive operations rotated the user’s security_stamp. That breaks the expected linkage between account security changes and token/session invalidation. NVD lists the issue as CVSS 3.1 6.8 (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N) and maps it to CWE-613. The vulnerable CPE range ends before 1.35.5.

Defensive priority

Medium. Patch promptly if you run affected Vaultwarden versions, because the flaw can preserve authenticated access after password or key changes. Token invalidation during recovery and account-hardening events should be treated as a core defense control.

Recommended defensive actions

  • Upgrade Vaultwarden to version 1.35.5 or later.
  • Review account-recovery, password-reset, KDF-change, key-rotation, email-change, organization admin reset, and emergency access takeover workflows for token invalidation expectations.
  • If you suspect exposure, assume previously issued refresh tokens may remain valid until the affected instance is updated and sessions are re-established.
  • Monitor authentication and refresh-token activity around account security changes for signs of continued session use after remediation steps.
  • Use the official GitHub advisory and NVD record to track any additional vendor guidance or clarification.

Evidence notes

The supplied NVD record marks the issue as analyzed and references the GitHub Security Advisory GHSA-6j4w-g4jh-xjfx. The CVSS vector is CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N, severity MEDIUM, and the weakness listed is CWE-613. The vulnerable CPE entry is cpe:2.3:a:dani-garcia:vaultwarden:*:*:*:*:*:*:*:* with versionEndExcluding 1.35.5. PublishedAt is 2026-05-11T23:20:21.837Z; modifiedAt is 2026-05-18T16:58:20.353Z.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-43911 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-43911

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-43911 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-43911

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.