Vulnerability in Mistralai Mistral-Vibe
CVE-2026-109428
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.
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/v2.25.5 (release-notes)
- github.com/mistralai/mistral-vibe/pull/1111 (issue-tracking, patch)
- github.com/mistralai/mistral-vibe/commit/c069ffa1e12fb5f2487b489217c40ab97721d5… (issue-tracking, patch)
- www.vulncheck.com/advisories/mistral-vibe-permission-bypass-via-bash-line-conti… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-109428?
- CVE-2026-109428 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-2026-109428?
- High severity. CVSS v3 base score is 8.8 out of 10.