{"id":"CVE-2026-107717","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-107717","generatedAt":"2026-10-28T03:39:48.676Z","title":"When an application renders untrusted data and passes the returned ChatMessage objects to an LLM provider, attacker-controlled JSON can cross the prompt boundary and become a system, assistant, or tool message because ChatMessage.role accepts arbitrary…","description":"Banks generates meaningful LLM prompts using a simple template language. Prior to 2.5.0, Banks Prompt.chat_messages() attempts to parse every line of rendered template output as ChatMessage JSON. When an application renders untrusted data and passes the returned ChatMessage objects to an LLM provider, attacker-controlled JSON can cross the prompt boundary and become a system, assistant, or tool message because ChatMessage.role accepts arbitrary strings. This can override application instructions, alter the intended prompt structure, or confuse downstream tool and message handling. This issue is fixed in version 2.5.0.","published":"2026-10-08T22:17:28.000Z","lastModified":"2026-10-13T17:17:17.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},"cwe":["CWE-20"],"affected":[],"epss":{"score":0.00335,"percentile":0.26764,"date":"2026-10-27","history":[{"date":"2026-10-09","score":0.00279,"percentile":0.18691}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-08T22:17:28.000Z","detail":{"score":"6.5","severity":"MEDIUM","publishedAt":"2026-10-08T22:17:27.560Z"},"summary":"New CVE, medium severity (CVSS 6.5)."}],"references":[{"url":"https://github.com/masci/banks/commit/02172b816fb84f6a824cc09a8aca7416f53c12cb","source":"security-advisories@github.com"},{"url":"https://github.com/masci/banks/pull/78","source":"security-advisories@github.com"},{"url":"https://github.com/masci/banks/releases/tag/v2.5.0","source":"security-advisories@github.com"},{"url":"https://github.com/masci/banks/security/advisories/GHSA-hmq2-7hp6-7crh","source":"security-advisories@github.com"},{"url":"https://github.com/masci/banks/security/advisories/GHSA-hmq2-7hp6-7crh","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-107717","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}