Out-of-bounds read in mod_auth_openidc - CVE-2026-54789

Vulnerability identifier: #VU136688

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-54789

CWE-ID: CWE-125

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary condition in the state-cookie parser of mod_auth_openidc. A remote attacker can trigger an out-of-bounds read error and cause a denial of service condition on the system.

mod_auth_openidc
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
openEuler
apache2-mod_auth_openidc-debuginfo
apache2-mod_auth_openidc
apache2-mod_auth_openidc-debugsource
mod_auth_openidc
mod_auth_openidc-debuginfo
mod_auth_openidc-debugsource

Install updates from vendor's website.

mod_auth_openidc - update to 2.4.19.4
apache2-mod_auth_openidc-debuginfo - update to 2.4.0-7.25.1
apache2-mod_auth_openidc - update to 2.4.0-7.25.1
apache2-mod_auth_openidc-debugsource - update to 2.4.0-7.25.1
mod_auth_openidc - update to 2.4.19.4-1
mod_auth_openidc-debuginfo - update to 2.4.19.4-1
mod_auth_openidc-debugsource - update to 2.4.19.4-1

• https://github.com/OpenIDC/mod_auth_openidc/security/advisories/GHSA-vgr5-qcpp-x2pr

• Denial of service in mod_auth_openidc
• openEuler 24.03 LTS SP4 update for mod_auth_openidc
• openEuler 24.03 LTS SP3 update for mod_auth_openidc
• openEuler 24.03 LTS SP1 update for mod_auth_openidc
• openEuler 22.03 LTS SP4 update for mod_auth_openidc
• SUSE update for apache2-mod_auth_openidc