the PhotoProofSheet handler can run commands

Published September 10, 2026 CVE-2026-73693

FileRun versions older than 2026.3.0 let an authenticated uploader run arbitrary commands on the server through a specially named uploaded file.

Severity
HighCVSS 3.1 · 8.8
Fix
Fixed in 2026.3.0
Affected versions
before 2026.3.0
Weakness
CWE-78OS Command Injection
Exploit likelihood
1.8% in 30 daysEPSS, higher than 77% of known flaws
Affects
FileRun
Exploited
Not confirmedNo confirmation recorded
CISA SSVC
No known exploitationAutomatable: no · Technical impact: total
EU ID
EUVD-2026-75598ENISA vulnerability database

How it works

  • An attacker needs a FileRun account with upload permission.
  • They upload a file with shell instructions in its name, then trigger FileRun's photo proof-sheet feature.
  • FileRun sends that filename through the server's command shell without safely separating it from the image-processing command.
  • The command runs with the web server's permissions.

What to do

Check the installed FileRun release and compare it with the VulnCheck advisory. versions older than 2026.3.0 are in scope.

Update FileRun to 2026.3.0, the first build that closes this vulnerability, using the vendor's official release. Until updating, FileRun says hiding the photo proof-sheet plugin from the control panel can reduce exposure.

Technical details

CVE-2026-73693 is an authenticated OS command injection in FileRun's PhotoProofSheet handler. A filename reaches ImageMagick's montage command through a shell without adequate escaping, allowing commands to run as the web-server user. FileRun fixed this vulnerability in 2026.3.0.

Severity breakdown

  • Attack vector Network Requires network access to the vulnerable service
  • Attack complexity Low Low complexity under the assessed conditions
  • Privileges required Low Attacker needs a basic user account
  • User interaction None No victim action needed
  • Scope Unchanged Impact stays within the same security authority
  • Confidentiality impact High Sensitive data can be exposed with serious impact
  • Integrity impact High Protected data can be changed with serious impact
  • Availability impact High The service can stop or suffer serious disruption
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Open in FIRST.org calculator

References