Vault Token Leaked to Backends via Authorization: Bearer Passthrough Header
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.4%
exploitation probability
0.4%top 65% of all CVEs
observed exploitation
nono source reports it
If a Vault auth mount is configured to pass through the "Authorization" header, and the "Authorization" header is used to authenticate to Vault, Vault forwarded the Vault token to the auth plugin backend. Fixed in 2.0.0, 1.21.5, 1.20.10, and 1.19.16.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
References
https://access.redhat.com/security/cve/CVE-2026-4525https://bugzilla.redhat.com/show_bug.cgi?id=2459107https://discuss.hashicorp.com/t/hcsec-2026-07-vault-may-expose-tokens-to-auth-plugins-due-to-incorrect-header-sanitization/77344https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4525.json