{"schemaVersion":3,"id":"CVE-2026-23943","aliases":["UBUNTU-CVE-2026-23943","DEBIAN-CVE-2026-23943"],"status":"published","duplicateOf":null,"title":null,"description":"Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion.\n\nThe 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.\n\nTwo compression algorithms are affected:\n\n* zlib: Activates immediately after key exchange, enabling unauthenticated attacks\n* zlib@openssh.com: Activates post-authentication, enabling authenticated attacks\n\nEach 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.\n\nThis 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.\n\nThis 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 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