{"id":"CVE-2026-53597","state":"PUBLISHED","title":"Prompty: Arbitrary code execution via JavaScript frontmatter in TypeScript loader","description":"Prompty is a markdown file format (.prompty) for LLM prompts. From 2.0.0-alpha.1 until 2.0.0-beta.3, the @prompty/core TypeScript loader in runtime/typescript/packages/core/src/core/loader.ts used gray-matter without overriding executable js and javascript frontmatter engines, allowing an attacker-controlled .prompty file with ---js frontmatter to execute arbitrary JavaScript during prompt loading. This issue is fixed in version 2.0.0-beta.3.","publishedAt":"2026-07-16T14:54:55.075Z","updatedAt":"2026-07-18T02:51:03.900Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["microsoft prompty"],"affected":[{"vendor":"microsoft","product":"prompty","versions":[{"version":">= 2.0.0-alpha.1, < 2.0.0-beta.3","status":"affected"}]}],"references":["https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw","https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853"],"weaknesses":["CWE-94"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53597.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53597","state":"PUBLISHED","datePublished":"2026-07-16T14:54:55.075Z","dateUpdated":"2026-07-18T02:51:03.900Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-09T19:39:52.404Z"},"containers":{"cna":{"title":"Prompty: Arbitrary code execution via JavaScript frontmatter in TypeScript loader","descriptions":[{"lang":"en","value":"Prompty is a markdown file format (.prompty) for LLM prompts. From 2.0.0-alpha.1 until 2.0.0-beta.3, the @prompty/core TypeScript loader in runtime/typescript/packages/core/src/core/loader.ts used gray-matter without overriding executable js and javascript frontmatter engines, allowing an attacker-controlled .prompty file with ---js frontmatter to execute arbitrary JavaScript during prompt loading. This issue is fixed in version 2.0.0-beta.3."}],"affected":[{"vendor":"microsoft","product":"prompty","versions":[{"version":">= 2.0.0-alpha.1, < 2.0.0-beta.3","status":"affected"}]}],"references":[{"url":"https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw","name":"https://github.com/microsoft/prompty/security/advisories/GHSA-c4gh-rv8h-q9vw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853","name":"https://github.com/microsoft/prompty/commit/c27402da2487075be577f06aa79df627fb9d6853","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-94","lang":"en","description":"CWE-94: Improper Control of Generation of Code ('Code Injection')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-16T14:54:55.075Z"},"source":{"advisory":"GHSA-c4gh-rv8h-q9vw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-18T02:50:54.007782Z","id":"CVE-2026-53597","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-18T02:51:03.900Z"}}]}}}