{"id":"DEBIAN-CVE-2026-107161","details":"A heap-based buffer overflow flaw was found in Cyrus SASL. The add_to_challenge() function in the DIGEST-MD5 plugin computes the size of the buffer needed for a challenge/response field before DIGEST-MD5 quoting is applied, but does not recompute that size when quoting (escaping special characters) makes the value longer. The under-sized buffer is then passed to strcat(), causing a heap-based out-of-bounds write whose size depends on attacker-controlled input. A malicious or on-path DIGEST-MD5 (or HTTP Digest) server can trigger this flaw in a connecting client by supplying a crafted challenge field, such as realm or nonce, most likely resulting in a crash of the client application.","modified":"2026-10-09T09:47:22.639059799Z","published":"2026-10-07T20:17:10.977Z","upstream":["CVE-2026-107161"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-107161"}],"affected":[{"package":{"name":"cyrus-sasl2","ecosystem":"Debian:12","purl":"pkg:deb/debian/cyrus-sasl2?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1.28+dfsg-10","2.1.28+dfsg-11","2.1.28+dfsg1-1","2.1.28+dfsg1-10","2.1.28+dfsg1-11","2.1.28+dfsg1-2","2.1.28+dfsg1-3","2.1.28+dfsg1-4","2.1.28+dfsg1-5","2.1.28+dfsg1-6","2.1.28+dfsg1-7","2.1.28+dfsg1-8","2.1.28+dfsg1-9"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-107161.json"}},{"package":{"name":"cyrus-sasl2","ecosystem":"Debian:13","purl":"pkg:deb/debian/cyrus-sasl2?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1.28+dfsg1-10","2.1.28+dfsg1-11","2.1.28+dfsg1-9"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-107161.json"}},{"package":{"name":"cyrus-sasl2","ecosystem":"Debian:14","purl":"pkg:deb/debian/cyrus-sasl2?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1.28+dfsg1-10","2.1.28+dfsg1-11","2.1.28+dfsg1-9"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-107161.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}