{"id":"CVE-2026-73259","state":"PUBLISHED","title":"Mongoose: Reflected XSS via decoded URI in directory listing render","description":"Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can send a crafted percent-encoded request path to a deployment using MG_ENABLE_DIRLIST and persuade a user to visit it. The mg_http_serve_dir() and listdir() path in src/http.c places the decoded request URI into the title and h1 elements without HTML entity encoding. The resulting reflected cross-site scripting executes in the Mongoose origin and can expose session data or perform actions as the victim. This issue is fixed in version 7.22.","publishedAt":"2026-08-20T17:39:16.147Z","updatedAt":"2026-08-20T19:51:19.095Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["cesanta mongoose"],"affected":[{"vendor":"cesanta","product":"mongoose","versions":[{"version":"< 7.22","status":"affected"}]}],"references":["https://github.com/cesanta/mongoose/security/advisories/GHSA-9cwm-487w-h25w","https://github.com/cesanta/mongoose/pull/3611","https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71","https://github.com/cesanta/mongoose/releases/tag/7.22"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/73xxx/CVE-2026-73259.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73259","state":"PUBLISHED","datePublished":"2026-08-20T17:39:16.147Z","dateUpdated":"2026-08-20T19:51:19.095Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-11T17:18:01.598Z"},"containers":{"cna":{"title":"Mongoose: Reflected XSS via decoded URI in directory listing render","descriptions":[{"lang":"en","value":"Mongoose is an embedded web server and network library. Prior to 7.22, a remote attacker can send a crafted percent-encoded request path to a deployment using MG_ENABLE_DIRLIST and persuade a user to visit it. The mg_http_serve_dir() and listdir() path in src/http.c places the decoded request URI into the title and h1 elements without HTML entity encoding. The resulting reflected cross-site scripting executes in the Mongoose origin and can expose session data or perform actions as the victim. This issue is fixed in version 7.22."}],"affected":[{"vendor":"cesanta","product":"mongoose","versions":[{"version":"< 7.22","status":"affected"}]}],"references":[{"url":"https://github.com/cesanta/mongoose/security/advisories/GHSA-9cwm-487w-h25w","name":"https://github.com/cesanta/mongoose/security/advisories/GHSA-9cwm-487w-h25w","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/cesanta/mongoose/pull/3611","name":"https://github.com/cesanta/mongoose/pull/3611","tags":["x_refsource_MISC"]},{"url":"https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71","name":"https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71","tags":["x_refsource_MISC"]},{"url":"https://github.com/cesanta/mongoose/releases/tag/7.22","name":"https://github.com/cesanta/mongoose/releases/tag/7.22","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-20T17:39:16.147Z"},"source":{"advisory":"GHSA-9cwm-487w-h25w","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/cesanta/mongoose/security/advisories/GHSA-9cwm-487w-h25w","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-20T19:50:57.116455Z","id":"CVE-2026-73259","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-20T19:51:19.095Z"}}]}}}