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CVE-2026-52747

HIGH
8.6
CVSS 3.1
Description
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 3.0.16, the multipart/form-data request body parser in libmodsecurity silently removes embedded line breaks from non-file form-field values before exporting them to ARGS and ARGS_POST because src/request_body_processor/multipart.cc overwrites reserved bytes in m_reserve instead of appending the current buffer. This creates a parser differential between ModSecurity and backend applications that preserve line breaks in form fields, allowing rules that inspect ARGS or ARGS_POST to miss payloads whose dangerous syntax depends on a line break. This issue is fixed in version 3.0.16.

Metadata

CVE ID
CVE-2026-52747
State
PUBLISHED
Assigner
GitHub_M
Reserved
2026-06-08 14:00 UTC
Published
2026-07-10 21:42 UTC
Last updated
2026-07-10 21:42 UTC
Primary CWE
CWE-180
CWE-180: Incorrect Behavior Order: Validate Before Canonical…
Vendor / Product
owasp-modsecurity / ModSecurity
Sources
cve.org  ·  NVD

Severity & Metrics

8.6 HIGH CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Affected products (1)
VendorProductPlatformVersions
owasp-modsecurity ModSecurity — < 3.0.16
Weakness (CWE)
CWESourceDescription
CWE-180 cna CWE-180: Incorrect Behavior Order: Validate Before Canonicalize
CVSS scores (1)
ScoreSeverityVersionSourceVector
8.6 HIGH 3.1 cna CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
References (3)
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