CVE-2026-104259

MEDIUM

MEDIUM Priority: 0.01 BB Relevance: 61/100

Published: 2026-11-09 Modified: 2026-11-12 First seen: 2026-11-09 Status: active

Attack Surface

Network No Auth No Interaction Scope Change

CVSS Vector Breakdown

AV: Network

AC: High

PR: None

UI: None

S: Changed

C: Low

I: Low

A: None

Description

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 2.9.15 and 3.0.17, msre_fn_removeComments_execute in apache2/re_tfns.c and inplace() in src/actions/transformations/remove_comments.cc implement t:removeComments by copying the character immediately after a comment terminator without re-evaluating it. Adjacent comments can therefore leave a later comment in the transformed value, allowing inline-comment obfuscation to bypass rules that depend on comment stripping. When a comment terminator is the final content, the same copy reads one byte beyond the input buffer. This issue is fixed in versions 2.9.15 and 3.0.17.

Weakness Classification (1)

CWE-670 — CWE-670: Always-Incorrect Control Flow Implementation

Affected Software (4)

Vendor	Product	Version
owasp-modsecurity	ModSecurity	< 2.9.15
owasp-modsecurity	ModSecurity	>= 3.0.0, < 3.0.17
owasp-modsecurity	ModSecurity	< 2.9.15
owasp-modsecurity	ModSecurity	>= 3.0.0, < 3.0.17