---
id: CVE-2026-52761
title: >-
  ModSecurity is an open source, cross platform web application firewall (WAF)
  engine for Apache, IIS and Nginx
summary: >-
  ModSecurity is an open source, cross platform web application firewall (WAF)
  engine for Apache, IIS and Nginx. From 3.0.0 through 3.0.15, the
  t:utf8toUnicode transformation in
  src/actions/transformations/utf8_to_unicode.cc produces wrong…
severity: medium
cvss: 5.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N'
cwe:
  - CWE-467
published: '2026-07-10'
updated: '2026-07-10'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-52761'
references:
  - url: >-
      https://github.com/owasp-modsecurity/ModSecurity/commit/edcd010814e234d46e2ec55a0f1078ff9d3032e4
    label: security-advisories@github.com
  - url: 'https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.16'
    label: security-advisories@github.com
  - url: >-
      https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-qjgm-7gp4-f8qq
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00411
epssPercentile: 0.32673
ingestedAt: '2026-07-11T22:16:00.538Z'
---

## Overview

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 through 3.0.15, the t:utf8toUnicode transformation in src/actions/transformations/utf8_to_unicode.cc produces wrong output on i386 architecture because snprintf uses sizeof on a char pointer rather than the length of the unicode buffer, allowing rules that use this transformation to be bypassed on i386 architecture. This issue is fixed in version 3.0.16.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.