CVE-2026-104269
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data tampering.
- Exploit odds
- 0.6% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.6% in the next 30 days (EPSS).
- Severity: 8.6 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.6% · EPSS, next 30 days
- Weakness
- CWE-436
- Record status
- Received
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
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
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-2026-104269.md and follow it. Check whether this project is affected by CVE-2026-104269. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/owasp-modsecurity/ModSecurity/commit/463db0c840fa27bfba095b0406a63004a12884b0
- https://github.com/owasp-modsecurity/ModSecurity/commit/c6bd53d2dd96766b3afdc35d9929ebb20925d13d
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v2.9.15
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.17
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-5pww-8rfg-9crf
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-5pww-8rfg-9crf
References
- https://github.com/owasp-modsecurity/ModSecurity/commit/463db0c840fa27bfba095b0406a63004a12884b0
- https://github.com/owasp-modsecurity/ModSecurity/commit/c6bd53d2dd96766b3afdc35d9929ebb20925d13d
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v2.9.15
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.17
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-5pww-8rfg-9crf
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-5pww-8rfg-9crf