Vulnerability in Mistralai Mistral-Vibe
CVE-2026-109429
Mistral Vibe before 2.25.4 contains a command permission gate bypass vulnerability that allows attackers to execute arbitrary commands by hiding a command substitution inside a single-quoted variable value that tree-sitter-bash static parsing cannot detect. Attackers can craft input such as embedding a command substitution within a single-quoted variable and re-expanding it with the ${var@P} prompt-transform operator so bash's promptvars feature executes the hidden command at runtime while only the trailing allowlisted command is classified, resulting in silent arbitrary command execution with the privileges of the agent's terminal session.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/mistralai/mistral-vibe/releases/tag/v2.25.4 (release-notes, patch)
- github.com/mistralai/mistral-vibe/pull/1084 (issue-tracking, patch)
- github.com/mistralai/mistral-vibe/commit/19b5b74faa78d0816b8d4d4c7d7543fc352067… (issue-tracking, patch)
- www.vulncheck.com/advisories/mistral-vibe-bash-permission-bypass-via-var-p-prom… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-109429?
- CVE-2026-109429 is a high-severity vulnerability in Mistralai Mistral-Vibe, classified under CWE-436. CVSS score: 8.8/10. Published 2026-10-13.
- How severe is CVE-2026-109429?
- High severity. CVSS v3 base score is 8.8 out of 10.