Affected versions of MISP allow any authenticated user to access TemplatesController::uploadFile() because the ACL entry for templates/uploadFile… (CVE-2026-86347)
A vulnerability in affected versions of MISP (up to 2.5.45) allows any authenticated user to access the TemplatesController::uploadFile() function due to a wildcard ACL entry. This bypasses intended role restrictions, enabling low-privileged or read-only users to upload arbitrary files repeatedly, consuming server disk space. The uploaded files receive random names, are stored outside the web root, and are not served over HTTP, preventing arbitrary file overwrite, stored XSS, or remote code execution.
AI Analysis
Technical Summary
The vulnerability arises from the ACL entry for templates/uploadFile using a wildcard (*) instead of a restrictive permission, allowing any authenticated user to invoke the uploadFile() method. This method accepts arbitrary content with minimal validation and writes files to app/tmp/files/. Because of the ACL misconfiguration, users without perm_add or perm_template privileges can upload files, leading to potential denial of service via disk space exhaustion. The fix involves changing the ACL requirement from * to perm_add. Additional safeguards such as random file naming, storage outside the web root, and no direct HTTP serving limit the impact to resource exhaustion rather than code execution or file overwrite.
Potential Impact
Authenticated users with low privileges can upload arbitrary files repeatedly, potentially exhausting server disk space and causing denial of service. There is no risk of arbitrary file overwrite, stored cross-site scripting, or remote code execution due to random file naming, storage location, and lack of direct HTTP access to uploaded files.
Mitigation Recommendations
A fix is available that changes the ACL requirement for templates/uploadFile from a wildcard to perm_add, restricting upload capability to authorized users. Users should upgrade to a version later than 2.5.45 where this fix is applied. Until patched, restrict authenticated user permissions to prevent abuse of the upload functionality.
Affected versions of MISP allow any authenticated user to access TemplatesController::uploadFile() because the ACL entry for templates/uploadFile… (CVE-2026-86347)
Description
A vulnerability in affected versions of MISP (up to 2.5.45) allows any authenticated user to access the TemplatesController::uploadFile() function due to a wildcard ACL entry. This bypasses intended role restrictions, enabling low-privileged or read-only users to upload arbitrary files repeatedly, consuming server disk space. The uploaded files receive random names, are stored outside the web root, and are not served over HTTP, preventing arbitrary file overwrite, stored XSS, or remote code execution.
CVSS v4.0
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability arises from the ACL entry for templates/uploadFile using a wildcard (*) instead of a restrictive permission, allowing any authenticated user to invoke the uploadFile() method. This method accepts arbitrary content with minimal validation and writes files to app/tmp/files/. Because of the ACL misconfiguration, users without perm_add or perm_template privileges can upload files, leading to potential denial of service via disk space exhaustion. The fix involves changing the ACL requirement from * to perm_add. Additional safeguards such as random file naming, storage outside the web root, and no direct HTTP serving limit the impact to resource exhaustion rather than code execution or file overwrite.
Potential Impact
Authenticated users with low privileges can upload arbitrary files repeatedly, potentially exhausting server disk space and causing denial of service. There is no risk of arbitrary file overwrite, stored cross-site scripting, or remote code execution due to random file naming, storage location, and lack of direct HTTP access to uploaded files.
Mitigation Recommendations
A fix is available that changes the ACL requirement for templates/uploadFile from a wildcard to perm_add, restricting upload capability to authorized users. Users should upgrade to a version later than 2.5.45 where this fix is applied. Until patched, restrict authenticated user permissions to prevent abuse of the upload functionality.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-798c-m5xg-4gf8
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-86347"]
- Ecosystems
- []
- Database Specific Severity
- HIGH
- Cvss Version
- 4.0
Threat ID: 6a9ee193acd9273b49e68bf8
Added to database: 09/07/2026, 16:08:51 UTC
Last enriched: 09/07/2026, 16:12:21 UTC
Last updated: 09/07/2026, 21:10:26 UTC
Views: 8
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