Medium severity · published Sep 7, 2026
CVE-2026-86347
MISP Missing Authorization on Template File Upload Allows Authenticated Disk Exhaustion
6.5
CVSS
0.4%
EPSS
No
On KEV
Description
Affected versions of MISP allow any authenticated user to access TemplatesController::uploadFile() because the ACL entry for templates/uploadFile used the wildcard *. This bypasses the intended role restrictions applied to neighboring template-management operations.
The upload handler accepts arbitrary content with only minimal checks and writes it into app/tmp/files/. A low-privileged or read-only user can therefore repeatedly upload files and consume server disk space without requiring perm_add or perm_template. The fix changes the ACL requirement from * to perm_add.
The commit also rules out stronger impacts: uploaded files receive random names, path traversal/predictable overwrite is not available, the temporary directory is outside the web root, and the files are not directly served over HTTP. Therefore, the issue should not be described as arbitrary file overwrite, stored XSS, or RCE.
Version affected: ≤2.5.45
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MI
MISP · MISP
through 2.5.45 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86347
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-86347
Patch
https://github.com/MISP/MISP/commit/8e8885971
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