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.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

0.6% chance of exploitation in the next 30 days; higher than 46% of CVEs (scores of 2026-10-25)

CWE

CWE-436

Published

2026-10-13

Modified

2026-10-16

Record from

the NVD, synced 2026-10-19

References

• https://github.com/mistralai/mistral-vibe/commit/19b5b74faa78d0816b8d4d4c7d7543fc3520678c
• https://github.com/mistralai/mistral-vibe/pull/1084
• https://github.com/mistralai/mistral-vibe/releases/tag/v2.25.4
• https://www.vulncheck.com/advisories/mistral-vibe-bash-permission-bypass-via-var-p-prompt-transform

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