What is CVE-2025-48866?

CVE-2025-48866 is a high-severity vulnerability in Owasp Modsecurity, classified under CWE-1050. CVSS score: 7.5/10. Published 2025-06-02.

How severe is CVE-2025-48866?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2025-48866 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Owasp Modsecurity

CVE-2025-48866

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.

Published 2025-06-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (56.8th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Owasp Modsecurity
Owasp-Modsecurity Modsecurity — versions < 2.9.10

Weakness classification (CWE)

CWE-1050

Public proof-of-concept exploits

w4zu/Debian_

References

github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-f82j-8pp7-cw2w (Exploit, Vendor Advisory)
github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-859r-vvv8-rm8r (Not Applicable)
github.com/owasp-modsecurity/ModSecurity/commit/3a54ccea62d3f7151bb08cb78d60c5e… (Patch)
github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x) (Product)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List)

Frequently asked questions

What is CVE-2025-48866?: CVE-2025-48866 is a high-severity vulnerability in Owasp Modsecurity, classified under CWE-1050. CVSS score: 7.5/10. Published 2025-06-02.
How severe is CVE-2025-48866?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2025-48866 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.