{"id":"DEBIAN-CVE-2026-29035","details":"CivetWeb (commit 4a4f0c95) contains a heap and stack buffer overflow vulnerability in the read_websocket() function that allows unauthenticated remote attackers to corrupt memory by sending compressed WebSocket frames when both USE_ZLIB and MG_EXPERIMENTAL_INTERFACES are defined. Attackers can negotiate permessage-deflate during the WebSocket handshake and send a crafted frame with the RSV1 bit set, causing the server to write a 4-byte zlib sync trailer out-of-bounds past the allocated buffer, leading to heap metadata corruption, denial of service, or potential code execution.","modified":"2026-09-25T09:00:08.968960089Z","published":"2026-08-11T21:17:35.507Z","upstream":["CVE-2026-29035"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-29035"}],"affected":[{"package":{"name":"civetweb","ecosystem":"Debian:12","purl":"pkg:deb/debian/civetweb?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.15+dfsg-4","1.16+dfsg-1","1.16+dfsg-2","1.16+dfsg-3","1.16+dfsg-4","1.16+dfsg-5","1.16+dfsg-6"],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-29035.json"}},{"package":{"name":"civetweb","ecosystem":"Debian:13","purl":"pkg:deb/debian/civetweb?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.16+dfsg-2","1.16+dfsg-2+deb13u1","1.16+dfsg-3","1.16+dfsg-4","1.16+dfsg-5","1.16+dfsg-6"],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-29035.json"}},{"package":{"name":"civetweb","ecosystem":"Debian:14","purl":"pkg:deb/debian/civetweb?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.16+dfsg-2","1.16+dfsg-3","1.16+dfsg-4","1.16+dfsg-5","1.16+dfsg-6"],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-29035.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}