CVE-2026-109428 Mistral Vibe < 2.25.5 Permission Bypass via Bash Line Continuation
Attackers can bypass permission checks in Mistral Vibe to execute arbitrary commands by exploiting line continuation parsing discrepancies.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-109428?
CVE-2026-109428 is a high-severity command injection vulnerability in mistralai mistral-vibe, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Mistral Vibe before 2.25.5 contains a permission validation bypass vulnerability that allows attackers to execute unauthorized commands by exploiting a parsing discrepancy between tree-sitter-bash and bash in handling backslash-newline line continuations in the _extract_commands() function of bash.py. Attackers can craft a command string where tree-sitter-bash extracts only an allowlisted prefix such as cd while bash joins the line continuation into a materially different and hidden command such as a curl request, causing resolve_permission to grant ALWAYS permission while bash executes unauthorized arbitrary commands.
Weakness: CWE-436
Which versions are affected by CVE-2026-109428?
How do I fix CVE-2026-109428?
No fix has been published for CVE-2026-109428 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-2026-109428 being exploited?
There is no known exploitation of CVE-2026-109428 in the wild and no public exploit code.
Sources
Also known as GHSA-66p3-rgrf-xjf3.