CVE-2026-55601 MultiTail: Shell injection in execute-on-match command handling
Attackers can execute arbitrary commands via shell metacharacters in log input when using the execute-on-match feature in MultiTail.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-55601?
CVE-2026-55601 is a high-severity command injection vulnerability in folkertvanheusden multitail, published on 13 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
MultiTail is a utility for monitoring multiple log files in one terminal. In version 7.1.5 and earlier, the -ex and -eX execute-on-match feature appended attacker-controlled matched input to a configured command inside double quotes, then check_filter_exec() in mt.c passed the constructed command through execute_program() in exec.c to sh -c. Partial escaping left shell metacharacters such as command substitution active, allowing an attacker who could influence monitored input to execute commands as the user running MultiTail. No fixed release is available as of this review.
Weakness: CWE-78
Which versions are affected by CVE-2026-55601?
How do I fix CVE-2026-55601?
No fix has been published for CVE-2026-55601 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-55601 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55601 exists.
Sources
Also known as GHSA-54vm-wwx8-856h.