{"id":"CVE-2026-58317","aliases":["EUVD-2026-45140","GHSA-mmcg-pw3p-cwjh"],"status":"published","title":"Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term...","description":"Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.","severity":{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0032,"percentile":0.2536,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-196"],"published":"2026-07-17T04:14:03Z","modified":"2026-10-24T20:10:00Z","products":[{"vendor":"teraterm project","product":"ttssh2"}],"references":[{"url":"https://teratermproject.github.io/SA/JVN65294474-en.html"},{"url":"https://teratermproject.github.io/SA/JVN65294474.html"},{"url":"https://jvn.jp/en/jp/JVN65294474/"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58317"},{"url":"https://jvn.jp/en/jp/JVN65294474"},{"url":"https://github.com/advisories/GHSA-mmcg-pw3p-cwjh"}],"sources":{"cve":[{"id":"CVE-2026-58317","description":"Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.","status":"published","published":"2026-07-17T04:14:03.592Z","modified":"2026-07-17T13:06:39.88Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.0","score":6.3,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-196"],"updated_at":"2026-11-02T13:47:39.876248Z"}],"euvd":[{"id":"EUVD-2026-45140","description":"Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.","status":"published","published":"2026-07-17T04:14:03Z","modified":"2026-07-17T13:06:39Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:19:50.846094Z"}],"ghsa":[{"id":"GHSA-mmcg-pw3p-cwjh","title":"Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term...","description":"Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.","status":"published","published":"2026-07-17T06:31:00Z","modified":"2026-07-17T06:31:06Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/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":"medium"},{"version":"3.0","score":6.3,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"cwes":["CWE-196"],"updated_at":"2026-11-02T15:09:34.599528Z"}],"nvd":[{"id":"CVE-2026-58317","description":"Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.","status":"published","published":"2026-07-17T05:16:40.18Z","modified":"2026-10-24T20:10:00.137Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/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":"medium","assessor":"secondary"},{"version":"3.0","score":6.3,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-196"],"updated_at":"2026-11-02T14:12:30.250437Z"}]}}