CVE-2025-48866

Public Exploit
ModSecurity has possible DoS vulnerability in sanitiseArg action

Description

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Versions prior to 2.9.10 contain a denial of service vulnerability similar to GHSA-859r-vvv8-rm8r/CVE-2025-47947. The `sanitiseArg` (and `sanitizeArg` - this is the same action but an alias) is vulnerable to adding an excessive number of arguments, thereby leading to denial of service. Version 2.9.10 fixes the issue. As a workaround, avoid using rules that contain the `sanitiseArg` (or `sanitizeArg`) action.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.04%
Vendor Advisory github.com
Affected: owasp-modsecurity ModSecurity
Published at:
Updated at:

References

Link Tags
https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-f82j-8pp7-cw2w exploit vendor advisory
https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-859r-vvv8-rm8r not applicable
https://github.com/owasp-modsecurity/ModSecurity/commit/3a54ccea62d3f7151bb08cb78d60c5e90b53ca2e patch
https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#sanitisearg product
https://lists.debian.org/debian-lts-announce/2025/06/msg00009.html mailing list

Frequently Asked Questions

What is the severity of CVE-2025-48866?
CVE-2025-48866 has been scored as a high severity vulnerability.
How to fix CVE-2025-48866?
To fix CVE-2025-48866, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-48866 being actively exploited in the wild?
It is possible that CVE-2025-48866 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-48866?
CVE-2025-48866 affects owasp-modsecurity ModSecurity.
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