{"id":"UBUNTU-CVE-2026-73259","details":"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.","modified":"2026-10-17T13:01:02.080762234Z","published":"2026-08-20T18:16:00Z","upstream":["CVE-2026-73259"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-73259"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-73259"}],"affected":[{"package":{"name":"mongoose","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/mongoose?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.21+ds-1","7.21+ds-2","7.22+ds-1","7.23+ds-1"],"ecosystem_specific":{"binaries":[{"binary_name":"mongoose-webserver-source","binary_version":"7.23+ds-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-73259.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}