mod_auth_openidc is an OpenID Certified authentication and authorization module for the Apache 2.x HTTP server that implements the OpenID Connect Relying Party functionality. Prior to 2.4.19.4, an out-of-bounds read and a one-byte out-of-bounds write exist in the state-cookie parser of `mod_auth_openidc`. The issue is fixed in version 2.4.19.4 by stopping the scan at the string terminator so a value-less token is rejected. No in-product workarounds are available. As a stop-gap, an upstream reverse proxy or WAF that rejects or normalizes malformed `Cookie` headers (tokens lacking `=`) can reduce exposure, but upgrading is the recommended remediation.
History

Fri, 21 Aug 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 21 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
First Time appeared Openidc
Openidc mod Auth Openidc
Vendors & Products Openidc
Openidc mod Auth Openidc

Fri, 21 Aug 2026 16:15:00 +0000

Type Values Removed Values Added
Description mod_auth_openidc is an OpenID Certified authentication and authorization module for the Apache 2.x HTTP server that implements the OpenID Connect Relying Party functionality. Prior to 2.4.19.4, an out-of-bounds read and a one-byte out-of-bounds write exist in the state-cookie parser of `mod_auth_openidc`. The issue is fixed in version 2.4.19.4 by stopping the scan at the string terminator so a value-less token is rejected. No in-product workarounds are available. As a stop-gap, an upstream reverse proxy or WAF that rejects or normalizes malformed `Cookie` headers (tokens lacking `=`) can reduce exposure, but upgrading is the recommended remediation.
Title mod_auth_openidc has out-of-bounds read and write in state cookie parsing
Weaknesses CWE-125
CWE-787
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-21T17:24:15.943Z

Reserved: 2026-06-15T23:23:57.714Z

Link: CVE-2026-54789

cve-icon Vulnrichment

Updated: 2026-08-21T17:23:38.049Z

cve-icon NVD

Status : Received

Published: 2026-08-21T16:17:19.000

Modified: 2026-08-21T18:16:48.680

Link: CVE-2026-54789

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T17:45:03Z