OS Command Injection in Discourse - #VU166163
Published: November 13, 2026
Vulnerability identifier: #VU166163
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-78
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote privileged user to execute arbitrary shell commands on the Discourse host.
The vulnerability exists due to improper neutralization of shell command elements in the Discourse uploads:gather rake task when processing upload records restored from a crafted backup. A remote privileged user can supply a backup containing malicious upload records to execute shell commands when a system administrator restores the backup and runs the task.
Affected software
Discourse
Remediation
Install security update from vendor's website.
Discourse - addressed in versions 2026.7.5, 2026.9.2, 2026.10.1