Skip to main content
HIGH

CVE-2025-3891

CVSS v3

7.5

HIGH

EPSS Score

1.6 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Get an alert for each new CVE published for apache.

Set up CVE WatchFree account · no credit card

Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • apacheBitnamiall versions · no fixed version listed
  • cjoseAlmaLinux:8all versions · fixed in 0.6.1-4.module_el8.10.0+3881+234adf82and 1 other package
  • mod_auth_openidcAlmaLinux:9all versions · fixed in 2.4.10-1.el9_6.2
  • mod_auth_openidcAlmaLinux:8all versions · fixed in 2.4.9.4-8.module_el8.10.0+3988+526f0275

Vendor advisories

  • CVE-2025-3891 Red Hat Product Security173 products fixed · 2 known affected

    mod_auth_openidc: DoS via Empty POST in mod_auth_openidc with OIDCPreservePost Enabled

    mod_auth_openidc as a component of Red Hat Enterprise Linux 10 · mod_auth_openidc.src as a component of Red Hat Enterprise Linux 10

  • RHSA-2025:10007 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: mod_auth_openidc security update

  • RHSA-2025:10010 Red Hat Product Security25 products fixed

    Red Hat Security Advisory: mod_auth_openidc:2.3 security update

  • RHSA-2025:10003 Red Hat Product Security48 products fixed

    Red Hat Security Advisory: mod_auth_openidc:2.3 security update

  • RHSA-2025:10004 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: mod_auth_openidc:2.3 security update

  • RHSA-2025:10008 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: mod_auth_openidc security update

4 more advisories

Full record on NVD

Description

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.

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2025-04-29
Last Modified
2026-06-29

Frequently asked questions

What is CVE-2025-3891?

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.

Is CVE-2025-3891 actively exploited?

Active exploitation of CVE-2025-3891 has not been confirmed. Its EPSS score was 1.6% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-3891?

CVE-2025-3891 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Running apache? Hear about its next vulnerability

CVE Watch matches each new CVE to the vendors and products you list (vendor and product, not the version) and puts it in your alerts with its KEV and EPSS status.

Get alerts for this productCISA KEV additions, October 2026Search CVEs

Already have an account? Open CVE WatchNo credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database