elFinder: ZIP extraction bypasses uploadDeny MIME filter allowing PHP file upload (RCE)
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-434.
Summary
elFinder is an open-source file manager for web, written in JavaScript using jQuery UI. Prior to 2.1.70, checkExtractItems() in php/elFinderVolumeDriver.class.php calls mimetypeInternalDetect() without passing the result through mimeTypeNormalize(). Because the .phtml, .phar, .php5, and .php3 extensions are absent from mime.types, the staticMimeMap entries that map them to text/x-php are not applied, and allowPutMime() permits extraction even when uploadDeny blocks text/x-php. An attacker with ZIP upload permission can extract PHP-executable files into a web-accessible files/ directory and achieve remote code execution when the server executes those extensions. This issue is fixed in version 2.1.70.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Studio-42 | elFinder | before 2.1.70 | 2.1.70 | Patch available | CNA |
| — | Studio-42/elFinder (Packagist) | before 2.1.70 | 2.1.70 | Patch available | GHSA-gxmj-r5rf-ggwq |
- elFinder VendorStudio-42 Affected before 2.1.70 Fixed in 2.1.70 Patch available CNA
- Studio-42/elFinder (Packagist) Vendor— Affected before 2.1.70 Fixed in 2.1.70 Patch available GHSA-gxmj-r5rf-ggwq
Remediation
- Fix · CNA elFinder (Studio-42) Fixed in 2.1.70
- Fix · GHSA-gxmj-r5rf-ggwq Studio-42/elFinder (Packagist) Fixed in 2.1.70 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-81891
- 2026-10-03 Alias added: GHSA-gxmj-r5rf-ggwq
References
Other 5
- https://github.com/Studio-42/elFinder/security/advisories/GHSA-gxmj-r5rf-ggwq
- https://github.com/Studio-42/elFinder/commit/191372c1bbebbd36fb55af79a84b9984861390ff
- https://github.com/Studio-42/elFinder/commit/dd73e702820c146a192969800ee674ecdb208365
- https://github.com/Studio-42/elFinder/releases/tag/2.1.70
- https://github.com/Studio-42/elFinder
More Studio-42 vulnerabilities
- TI-2026-56500 elFinder: SSRF protection bypass via DNS rebinding in the `fsock_get_contents()` fallback CVSS 3.1HIGH 8.6
- TI-2026-56501 elFinder: CSRF in netmount allows forced FTP mounts and server-side FTP connections CVSS 3.1MEDIUM 5.4
- TI-2026-32450 elFinder: SQL Injection MySQL Volume Driver (elFinderVolumeMySQL) CVSS 3.1HIGH 8.8
Sources
- CVE-2026-81891 · CVE Program
- CVE-2026-81891 · NVD
- FIRST EPSS
- GHSA-gxmj-r5rf-ggwq · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences