{"id":"DEBIAN-CVE-2026-93394","details":"A flaw in libmongoc's SCRAM authentication implementation caused the client to continue the authentication handshake and transmit the client proof even when a nonce mismatch was detected in the server's first message. An unauthorized party with a man-in-the-middle position could exploit this by injecting a crafted server-first-message containing a controlled salt and low iteration count, then capturing the resulting client proof to perform offline password cracking. This vulnerability is mitigated by TLS, which is standard in production deployments.","modified":"2026-09-26T09:00:22.163403740Z","published":"2026-09-17T21:17:56.307Z","upstream":["CVE-2026-93394"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-93394"}],"affected":[{"package":{"name":"mongo-c-driver","ecosystem":"Debian:12","purl":"pkg:deb/debian/mongo-c-driver?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.23.1-1","1.23.1-1+deb12u1","1.23.1-1+deb12u2","1.23.1-1+deb12u3","1.24.1-1","1.24.2-1","1.24.3-1","1.24.4-1","1.25.0-1","1.25.1-1","1.25.2-1","1.25.4-1","1.25.4-1.1~exp1","1.26.0-1","1.26.0-1.1","1.26.0-1.1~exp1","1.26.1-1","1.26.2-1","1.27.0-1","1.27.1-1","1.27.2-1","1.27.3-1","1.27.4-1","1.27.5-1","1.27.6-1","1.28.0-1","1.28.1-1","1.29.0-1","1.29.1-1","1.29.2-1","1.30.0-1","1.30.1-1","1.30.2-1","1.30.3-1","1.30.4-1","2.0.2-1","2.1.0-1","2.1.1-1","2.1.2-1","2.2.0-1","2.2.1-1","2.2.2-1","2.2.3-1","2.2.4-1","2.3.0-1","2.3.1-1","2.3.2-1","2.3.3-1","2.4.0-1","2.5.0-1","2.5.1-1","2.5.2-1","2.5.3-1","2.5.5-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-93394.json"}},{"package":{"name":"mongo-c-driver","ecosystem":"Debian:13","purl":"pkg:deb/debian/mongo-c-driver?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.30.4-1","1.30.4-1+deb13u1","1.30.4-1+deb13u2","1.30.4-1+deb13u3","2.0.2-1","2.1.0-1","2.1.1-1","2.1.2-1","2.2.0-1","2.2.1-1","2.2.2-1","2.2.3-1","2.2.4-1","2.3.0-1","2.3.1-1","2.3.2-1","2.3.3-1","2.4.0-1","2.5.0-1","2.5.1-1","2.5.2-1","2.5.3-1","2.5.5-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-93394.json"}},{"package":{"name":"mongo-c-driver","ecosystem":"Debian:14","purl":"pkg:deb/debian/mongo-c-driver?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.0-1"}]}],"versions":["1.30.4-1","2.0.2-1","2.1.0-1","2.1.1-1","2.1.2-1","2.2.0-1","2.2.1-1","2.2.2-1","2.2.3-1","2.2.4-1","2.3.0-1","2.3.1-1","2.3.2-1","2.3.3-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-93394.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/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"}]}