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TI-2026-37865 Aliases CVE-2026-52747

ModSecurity: Multipart form-data parser silently strips embedded line breaks from…

Priority HIGH 76CWE-180Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00476 41st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial ModSecurity (owasp-modsecurity): 3.0.16Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
owasp-modsecurityModSecuritybefore 3.0.163.0.16Patch availableCNA
  • ModSecurity Vendorowasp-modsecurity Affected before 3.0.16 Fixed in 3.0.16 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:owasp:modsecurity:*:*:*:*:*:*:*:*before 3.0.16Vulnerableowasp-modsecurity
  • cpe:2.3:a:owasp:modsecurity:*:*:*:*:*:*:*:* Versions before 3.0.16 Vulnerable ·owasp-modsecurity

Remediation

  • Fix · CNA ModSecurity (owasp-modsecurity) Fixed in 3.0.16

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-52747

References

Exploit 1

Patch 1

Other 1

  • TI-2026-30581 ModSecurity: Unsigned integer underflow in @verifySSN / @verifyCPF / @verifySVNR operators CVSS 4.0HIGH 8.2
  • TI-2026-23748 libModSecurity3 denial of service via segfault when using t:hexDecode on single-character query strings CVSS 4.0HIGH 8.2
  • TI-2025-31022 ModSecurity has possible DoS vulnerability in sanitiseArg action CVSS 3.1HIGH 7.5
  • TI-2025-34348 ModSecurity's Insufficient Return Value Handling can Lead to XSS and Source Code Disclosure CVSS 4.0MEDIUM 6.9
  • TI-2024-00942 WAF bypass of the ModSecurity v3 release line CVSS 3.1HIGH 8.6
  • TI-2023-19686 Trustwave ModSecurity 3.x before 3.0.10 has Inefficient Algorithmic Complexity. CVSS 3.1HIGH 7.5
See all 14 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences