Cyber Resilience

CVE-2026-52747

Owasp Modsecurity ≤ 3.0.16

Public PoC
Published
10 July 2026
Modified
14 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
EPSS Score 0.0052 42th percentile
Risk Priority 62 floored blend · peak EPSS

Summary

CVE-2026-52747 is a high-severity Incorrect Behavior Order: Validate Before Canonicalize (CWE-180) vulnerability in Owasp Modsecurity. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-180

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1027 Obfuscated Files or Information Stealth
Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-52761Same product: Owasp Modsecurity
CVE-2024-1019Same product: Owasp Modsecurity
CVE-2026-30923Same product: Owasp Modsecurity
CVE-2026-42268Same product: Owasp Modsecurity
CVE-2025-54571Same product: Owasp Modsecurity
CVE-2023-28882Same product: Owasp Modsecurity
CVE-2025-48866Same product: Owasp Modsecurity
CVE-2023-38285Same product: Owasp Modsecurity
CVE-2026-39409Shared CWE-180
CVE-2024-28607Shared CWE-180

Affected Assets

owasp
modsecurity
≤ 3.0.16

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.3.8
  • V1.1.1
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

SA-11 requires developer testing and evaluation that can discover validation-order defects after they have been coded.

SI-10 Information Input Validation good match

SI-10 requires validity checks on inputs; when implemented with canonicalization preceding validation it structurally prevents the exact ordering flaw.

SA-8 Security and Privacy Engineering Principles partial match

SA-8 mandates security engineering principles that include correct canonicalization-before-validation ordering for input handling.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require correct validation order after canonicalization to prevent bypasses.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect validation-order defects before deployment.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and canonicalization order, directly addressing CWE-180.

A.8.26 Application security requirements partial match
prevents

Application security requirements include proper input handling to prevent validation-before-canonicalization flaws.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce the likelihood of ordering errors in input processing.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly require canonicalize-then-validate to eliminate CWE-180.

References