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CVE-2026-104269

8.6 high

High (8.6) in owasp-modsecurity modsecurity.

On this page
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 until 3.0.17, ModSecurity's multipart parser does not apply the RFC 2231 filename* parameter precedence used by common Go, Python, Node.js, and Java application parsers. A Content-Disposition header can provide a benign filename parameter for ModSecurity and a different encoded filename* value that the backend prefers, causing MULTIPART_FILENAME rules and the application to make security decisions on different names. Applications that use the backend-selected name for storage, extension checks, or content-type inference can therefore receive a filename that bypassed WAF inspection. PHP's native multipart parser is not affected by this discrepancy. This issue is fixed in version 3.0.17.

Severity

CVSS 3.1

8.6 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
CWE
CWE-436 Interpretation Conflict
OWASP Top 10
A06:2025 Insecure Design
Published
Record from
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Affected

Versions

From the CNA's record in the CVE List.

ProductAffected
owasp-modsecurity ModSecurity>= 3.0.0, < 3.0.17

Linux distributions

DistributionReleasePackageFixed inAdvisory
Debian12, 13, 14modsecurity, modsecurity-apacheno fix listedDEBIAN-CVE-2026-104269
Ubuntu20.04:LTS, 22.04:LTS, 24.04:LTSmodsecurityno fix listedUBUNTU-CVE-2026-104269
Ubuntu26.04:LTS, 26.10modsecurity, modsecurity-apacheno fix listedUBUNTU-CVE-2026-104269
UbuntuPro:14.04:LTS, Pro:16.04:LTS, Pro:18.04:LTS and 3 moremodsecurity-apacheno fix listedUBUNTU-CVE-2026-104269

From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.

Attack patterns (CAPEC)

  • CAPEC-34 HTTP Response Splitting Likelihood: Medium · Severity: High
  • CAPEC-105 HTTP Request Splitting Likelihood: Medium · Severity: High
  • CAPEC-273 HTTP Response Smuggling Likelihood: Medium · Severity: High

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.

References

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