CVE-2026-52747

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-10 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-25 15:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-07-10 22:16 UTC

Last modified

2026-10-25 15:10 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-180

Record status

Analyzed

Affected

• Owasp Modsecurity < 3.0.16

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-52747.md and follow it. Check whether this project is affected by CVE-2026-52747. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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