Incorrect authorization in mod_auth_openidc - #VU159581
Published: November 6, 2026
Vulnerability identifier: #VU159581
CSH Severity: Low
CVSS v4: 7.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a low-privileged remote attacker to access a higher-trust resource server using a lower-trust server’s valid token.
The vulnerability exists due to mod_auth_openidc caching validation results without binding them to verifiers in non-default OAuth resource-server deployments where differently trusted virtual hosts share a cache and OIDCCryptoPassphrase. A low-privileged remote attacker can submit the token to the lower-trust host, then replay it against the target to bypass validation, provided local JWT issuer/audience checks do not exclude it.
Affected software
mod_auth_openidc
Remediation
Install security update from vendor's website.
mod_auth_openidc - update to 2.4.20.4