CVE-2026-124028

MEDIUM 4.2

mistral.rs before 0.9.5 Tool Call Injection via mistralrs-core Output Parsers

CVSS Score

4.2

EPSS Score

0.0%

EPSS Percentile

0th

mistral.rs before 0.9.5 contains a delimiter injection vulnerability in mistralrs-core that allows attackers to inject tool calls by placing delimiter strings in text the model quotes. Attackers controlling documents, web pages or tool outputs can embed tags like </tool_call> to make qwen-xml, gemma4 or reasoning parsers return extra calls to declared tools with attacker-chosen arguments.

CWE	CWE-140
Vendor	ericlbuehler
Product	mistral.rs
Published	Nov 6, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

EricLBuehler / mistral.rs

0 < 0.9.5

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/EricLBuehler/mistral.rs/commit/b43d3443e946752c0f662c2df42a2974410c9532 github.com: https://github.com/EricLBuehler/mistral.rs github.com: https://github.com/EricLBuehler/mistral.rs/security/advisories/GHSA-34w8-j94f-8c5w github.com: https://github.com/EricLBuehler/mistral.rs/pull/2455 github.com: https://github.com/EricLBuehler/mistral.rs/releases/tag/v0.9.5 vulncheck.com: https://www.vulncheck.com/advisories/mistral-rs-before-0.9.5-tool-call-injection-via-mistralrs-core-output-parsers

Credits

Taehun Kim Youngjoo Shin Eric Buehler