{"id":"CVE-2026-124028","state":"PUBLISHED","title":"mistral.rs before 0.9.5 Tool Call Injection via mistralrs-core Output Parsers","description":"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.","publishedAt":"2026-11-06T19:14:45.628Z","updatedAt":"2026-11-06T19:14:45.628Z","severity":{"score":2.3,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["EricLBuehler mistral.rs"],"affected":[{"vendor":"EricLBuehler","product":"mistral.rs","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"0.9.5","versionType":"semver"}]}],"references":["https://github.com/EricLBuehler/mistral.rs/commit/b43d3443e946752c0f662c2df42a2974410c9532","https://github.com/EricLBuehler/mistral.rs","https://github.com/EricLBuehler/mistral.rs/security/advisories/GHSA-34w8-j94f-8c5w","https://github.com/EricLBuehler/mistral.rs/pull/2455","https://github.com/EricLBuehler/mistral.rs/releases/tag/v0.9.5","https://www.vulncheck.com/advisories/mistral-rs-before-0.9.5-tool-call-injection-via-mistralrs-core-output-parsers"],"weaknesses":["CWE-140"],"ingestedAt":"2026-11-06T19:20:06.668Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/124xxx/CVE-2026-124028.json","commit":"64a2fc3fb51a0d352ce39f4daed428c7f43508b1","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-124028","state":"PUBLISHED","datePublished":"2026-11-06T19:14:45.628Z","dateUpdated":"2026-11-06T19:14:45.628Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-11-06T18:51:27.537Z"},"containers":{"cna":{"title":"mistral.rs before 0.9.5 Tool Call Injection via mistralrs-core Output Parsers","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"EricLBuehler","product":"mistral.rs","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"0.9.5","versionType":"semver"}]}],"references":[{"url":"https://github.com/EricLBuehler/mistral.rs/commit/b43d3443e946752c0f662c2df42a2974410c9532","tags":["patch"],"name":"Patch Commit"},{"url":"https://github.com/EricLBuehler/mistral.rs","tags":["product"]},{"url":"https://github.com/EricLBuehler/mistral.rs/security/advisories/GHSA-34w8-j94f-8c5w","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-34w8-j94f-8c5w)"},{"url":"https://github.com/EricLBuehler/mistral.rs/pull/2455","tags":["issue-tracking","patch"]},{"url":"https://github.com/EricLBuehler/mistral.rs/releases/tag/v0.9.5","tags":["release-notes"],"name":"mistral.rs v0.9.5 Release Notes"},{"url":"https://www.vulncheck.com/advisories/mistral-rs-before-0.9.5-tool-call-injection-via-mistralrs-core-output-parsers","name":"VulnCheck Advisory: mistral.rs before 0.9.5 Tool Call Injection via mistralrs-core Output Parsers","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":2.3,"baseSeverity":"LOW"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":4.2,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-140","lang":"en","description":"Improper Neutralization of Delimiters","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-11-06T19:14:45.628Z"},"datePublic":"2026-09-25T00:00:00.000Z","credits":[{"lang":"en","value":"Taehun Kim","type":"finder"},{"lang":"en","value":"Youngjoo Shin","type":"finder"},{"lang":"en","value":"Eric Buehler","type":"remediation developer"}],"x_generator":{"engine":"vulncheck-endgame"}}}}}