CVE-2025-3891: http server (CVSS 7.5)

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-248 CWE-248

Affected Products

Vendor	Product	Versions
apache	http_server	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
debian	debian_linux	All

References

Other References

https://access.redhat.com/errata/RHSA-2025:10002 https://access.redhat.com/errata/RHSA-2025:10003 https://access.redhat.com/errata/RHSA-2025:10004 https://access.redhat.com/errata/RHSA-2025:10006 https://access.redhat.com/errata/RHSA-2025:10007 https://access.redhat.com/errata/RHSA-2025:10008 https://access.redhat.com/errata/RHSA-2025:10010 https://access.redhat.com/errata/RHSA-2025:4597 https://access.redhat.com/errata/RHSA-2025:9396 https://access.redhat.com/security/cve/CVE-2025-3891

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-3891? +

CVE-2025-3891 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-3891? +

CVE-2025-3891 affects products from apache, debian, redhat, specifically: debian_linux, enterprise_linux, http_server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-3891? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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