{"id":"CVE-2026-129122","summary":"C-Kermit 6.0.192 before 11.1.515 Buffer Overflow via Telnet NEW-ENVIRON Negotiation","details":"C-Kermit 6.0.192 before 11.1.515 contains a buffer overflow vulnerability in tn_snenv() in ckctel.c that allows malicious Telnet servers to corrupt client memory via crafted NEW-ENVIRON SEND subnegotiation. Malicious or machine-in-the-middle servers can send oversized variable names before authentication, overflowing a 16-byte stack buffer and a miscomputed heap buffer to corrupt stack and heap memory.","aliases":["CVE-2026-129123","CVE-2026-129124","CVE-2026-129125","CVE-2026-129126","GHSA-c5px-7h4c-gj8p"],"modified":"2026-11-14T02:56:11.103243781Z","published":"2026-11-13T16:23:44.625Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-787"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/129xxx/CVE-2026-129122.json","unresolved_ranges":[{"extracted_events":[{"strategy":"StandardRange","range":[{"introduced":"6.0.192"},{"fixed":"11.1.515"}],"source":"AFFECTED_FIELD"}]},{"extracted_events":[{"range":[{"introduced":"6.0.192"},{"fixed":"11.1.515"}],"source":"DESCRIPTION"}]}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/129xxx/CVE-2026-129122.json"},{"type":"ARTICLE","url":"https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckctel.c#L5622"},{"type":"FIX","url":"https://github.com/OpenKermit/ckermit/commit/39ab009a365b97632e9975e1266fa618c4bdc59f"},{"type":"FIX","url":"https://github.com/OpenKermit/ckermit/commit/42cf6decb926f56d606a76262791aaf071955d25"},{"type":"ADVISORY","url":"https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515"},{"type":"ADVISORY","url":"https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-129122"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/c-kermit-6.0.192-before-11.1.515-buffer-overflow-via-telnet-new-environ-negotiation"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openkermit/ckermit","events":[{"introduced":"0"},{"fixed":"39ab009a365b97632e9975e1266fa618c4bdc59f"},{"fixed":"42cf6decb926f56d606a76262791aaf071955d25"}],"database_specific":{"extracted_events":[{"range":[{"fixed":"39ab009a365b97632e9975e1266fa618c4bdc59f"}],"source":"REFERENCES_COMMIT"},{"source":"REFERENCES_COMMIT","range":[{"fixed":"42cf6decb926f56d606a76262791aaf071955d25"}]}]}}],"versions":["v11.0.514","v11.0.513","v11.0.512","v11.0.511","v11.0.510","v11.0.509","v11.0.508","v11.0.507","v11.0.506","v11.0.505","v11.0.504","v11.0.503","v11.0.502","v11.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-129122.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}