{"id":"DEBIAN-CVE-2026-23943","details":"Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.  The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS.  Two compression algorithms are affected:  * zlib: Activates immediately after key exchange, enabling unauthenticated attacks * zlib@openssh.com: Activates post-authentication, enabling authenticated attacks  Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments.  This vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4.  This issue affects OTP from OTP 17.0 before OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to ssh from 3.0.1 before 5.5.1, 5.2.11.6 and 5.1.4.14.","modified":"2026-09-01T16:06:35.886364587Z","published":"2026-03-13T19:54:15.783Z","upstream":["CVE-2026-23943"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-23943"}],"affected":[{"package":{"name":"erlang","ecosystem":"Debian:12","purl":"pkg:deb/debian/erlang?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:25.2.3+dfsg-1+deb12u4"}]}],"versions":["1:25.2.3+dfsg-1","1:25.2.3+dfsg-1+deb12u1","1:25.2.3+dfsg-1+deb12u2","1:25.2.3+dfsg-1+deb12u3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23943.json"}},{"package":{"name":"erlang","ecosystem":"Debian:13","purl":"pkg:deb/debian/erlang?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:27.3.4.1+dfsg-1+deb13u2"}]}],"versions":["1:27.3.4.1+dfsg-1","1:27.3.4.1+dfsg-1+deb13u1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23943.json"}},{"package":{"name":"erlang","ecosystem":"Debian:14","purl":"pkg:deb/debian/erlang?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:27.3.4.9+dfsg-1"}]}],"versions":["1:27.3.4.1+dfsg-1","1:27.3.4.3+dfsg-1","1:27.3.4.4+dfsg-1","1:27.3.4.6+dfsg-1","1:27.3.4.8+dfsg-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23943.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}