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Vulnerabilities

Vulnerability · CVE-2025-3891

A flaw was found in the mod_auth_openidc module for Apache httpd.

Published Apr 29, 2025 · catalog updated Jun 29, 2026 · Red Hat Red Hat Enterprise Linux 8

Check if you run it

No confirmed exploitation is on record for CVE-2025-3891. EPSS is 1.58%. Act only if a listed version of Red Hat Red Hat Enterprise Linux 8 is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
1.58%
Remediation
Vendor / distro source
Affected products
vendor Red Hat Red Hat Enterprise Linux 8 patch: 8100020250426100353.489197e6

A flaw was found in the mod_auth_openidc module for Apache httpd. This flaw allows a remote, unauthenticated attacker to trigger a denial of service by sending an empty POST request when the OIDCPreservePost directive is enabled. The server crashes consistently, affecting availability.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Red Hat Red Hat Enterprise Linux 8 patch: 8100020250426100353.489197e6patch: 8100020250426100353.489197e6

How to fix CVE-2025-3891

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-3891. EPSS is 1.58%. Act only if a listed version of Red Hat Red Hat Enterprise Linux 8 is installed.

Which versions are affected?

Compare what you have installed with Red Hat Red Hat Enterprise Linux 8 patch: 8100020250426100353.489197e6 patch: 8100020250426100353.489197e6. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 1.58%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 29, 2025 · EUVD

    Detected

    A flaw was found in the mod_auth_openidc module for Apache httpd. This flaw allows a remote, unauthenticated attacker to trigger a denial of service by sending an empty POST request when the OIDCPreservePost directive is enabled. The server crashes consistently, affecting availability.

  2. Jun 29, 2026 · EUVD

    Updated

    A flaw was found in the mod_auth_openidc module for Apache httpd. This flaw allows a remote, unauthenticated attacker to trigger a denial of service by sending an empty POST request when the OIDCPreservePost directive is enabled. The server crashes consistently, affecting availability.

Sources

  • CVE.orgVulnerability recordCVE-2025-3891

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-3891

    30-day exploitation probability 1.6%

    first.org
  • EUVDVulnerability recordEUVD-2025-13653

    A flaw was found in the mod_auth_openidc module for Apache httpd. This flaw allows a remote, unauthenticated attacker to trigger a denial of service by sending an empty POST request when the OIDCPreservePost directive is enabled. The server crashes consistently, affecting availab

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.