{"id":"CVE-2026-121969","aliases":["EUVD-2026-117080","GHSA-2v39-q9qf-3m9g","UBUNTU-CVE-2026-121969"],"status":"published","title":"netrek-client-cow through 3.3.3 Stack Buffer Overflow via handleSMessage","description":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","severity":{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00344,"percentile":0.28352,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-121"],"published":"2026-11-04T20:36:47Z","modified":"2026-11-06T01:05:02Z","affected":[{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"netrek-client-cow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.0-3.1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"netrek-client-cow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.1-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"netrek-client-cow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.1-4build1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"netrek-client-cow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"netrek-client-cow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1","3.3.2-1build1","3.3.2-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"netrek-client-cow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1build3","3.3.3-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"netrek-client-cow","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1build2","3.3.2-1build3"]}],"products":[{"vendor":"quozl","product":"netrek-client-cow"}],"references":[{"url":"https://github.com/quozl/netrek-client-cow/commit/fb322e74abee3b0b76a9c5a31df6aab5585d3127","tags":["patch","fix","report"]},{"url":"https://github.com/quozl/netrek-client-cow","tags":["product","package","report"]},{"url":"https://github.com/quozl/netrek-client-cow/blob/3.3.3/short.c#L949","tags":["technical-description","article","report"]},{"url":"https://github.com/quozl/netrek-client-cow/issues/11","tags":["issue-tracking","report"]},{"url":"https://www.vulncheck.com/advisories/netrek-client-cow-through-3.3.3-stack-buffer-overflow-via-handlesmessage","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121969","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-2v39-q9qf-3m9g"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121969.json","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-121969","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-121969","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-121969","title":"netrek-client-cow through 3.3.3 Stack Buffer Overflow via handleSMessage","description":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","status":"published","published":"2026-11-04T20:36:47.609Z","modified":"2026-11-05T19:27:21.478Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-121"],"updated_at":"2026-11-05T20:54:59.423743Z"}],"euvd":[{"id":"EUVD-2026-117080","description":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","status":"published","published":"2026-11-04T20:36:47Z","modified":"2026-11-05T19:27:21Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-05T20:01:48.21368Z"}],"ghsa":[{"id":"GHSA-2v39-q9qf-3m9g","title":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in...","description":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","status":"published","published":"2026-11-04T21:32:31Z","modified":"2026-11-04T21:32:32Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/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","level":"high"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-121"],"updated_at":"2026-11-04T21:42:45.289646Z"}],"nvd":[{"id":"CVE-2026-121969","description":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","status":"published","published":"2026-11-04T21:18:06.84Z","modified":"2026-11-05T20:17:49.277Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/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","level":"high","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-121"],"updated_at":"2026-11-05T21:56:49.714113Z"}],"osv":[{"id":"CVE-2026-121969","title":"netrek-client-cow through 3.3.3 Stack Buffer Overflow via handleSMessage","description":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","status":"published","published":"2026-11-04T20:36:47.609Z","modified":"2026-11-07T07:05:09.031657993Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-121"],"updated_at":"2026-11-07T03:08:01.726202Z"},{"id":"UBUNTU-CVE-2026-121969","description":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","status":"published","published":"2026-11-05T00:00:00Z","modified":"2026-11-06T01:00:36.925511558Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"},{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-06T01:33:05.666804Z"}]}}