What is CVE-2026-43911?

CVE-2026-43911 is a medium-severity vulnerability in Dani-Garcia Vaultwarden, classified under Insufficient Session Expiration. CVSS score: 6.8/10. Published 2026-05-11.

How severe is CVE-2026-43911?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Vulnerability in Dani-Garcia Vaultwarden

CVE-2026-43911

Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to 1.35.5, refresh tokens are not invalidated when the user's security_stamp is rotated by some security-sensitive operations (password change, KDF change, key rotation, email change, org admin password reset, emergency access takeover). This allows an attacker holding a previously obtained refresh token to maintain session access even after the user has taken action to secure their account. This vulnerability is fixed in 1.35.5.

Published 2026-05-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.2th percentile), scored 2026-09-23.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Dani-Garcia Vaultwarden — versions < 1.35.5

Weakness classification (CWE)

CWE-613 — Insufficient Session Expiration

References

github.com/dani-garcia/vaultwarden/security/advisories/GHSA-6j4w-g4jh-xjfx (Exploit, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-43911?: CVE-2026-43911 is a medium-severity vulnerability in Dani-Garcia Vaultwarden, classified under Insufficient Session Expiration. CVSS score: 6.8/10. Published 2026-05-11.
How severe is CVE-2026-43911?: Medium severity. CVSS v3 base score is 6.8 out of 10.