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CVE-2026-52747

Owasp Modsecurity vulnerability

8.6 HIGHPublic exploitEPSS 0.48%
  1. Published10 Jul 2026

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Affected products

Owasp Modsecurity< 3.0.16

Remediation

Fixed in
Owasp Modsecurity≥ 3.0.16

References

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Frequently asked

Is CVE-2026-52747 being actively exploited?

CVE-2026-52747 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.48%.

How severe is CVE-2026-52747?

CVE-2026-52747 has a CVSS 3.1 base score of 8.6, rated high. EPSS estimates a 0.48% probability of exploitation.

Which products are affected by CVE-2026-52747?

Affected products include Owasp Modsecurity.

How do I fix CVE-2026-52747?

Upgrade affected software to a fixed version, for example Owasp Modsecurity 3.0.16 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-52747 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.