{"id":"CVE-2026-48852","aliases":["DEBIAN-CVE-2026-48852","EUVD-2026-31735","GHSA-rx8r-f2xx-98h9","UBUNTU-CVE-2026-48852","openSUSE-SU-2026:12168-1","openSUSE-SU-2026:22127-1"],"status":"published","title":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","description":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","severity":{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00275,"percentile":0.20033,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-617"],"published":"2026-05-25T20:19:20Z","modified":"2026-10-20T19:15:04Z","fixes":[{"ecosystem":"Debian:14","package":"putty","fixed_in":["0.84-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.78-2","0.78-2+deb12u1","0.78-2+deb12u2","0.78-3","0.79-1","0.80-1","0.81-1","0.81-2","0.81-3","0.82-1","0.82-2","0.83-1","0.83-2","0.83-3","0.84-1","0.85-3"]},{"source":"osv","ecosystem":"Debian:13","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.83-3","0.84-1","0.85-3"]},{"source":"osv","ecosystem":"Debian:14","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.84-1"}]}],"versions":["0.83-3"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.65-2","0.66-1","0.66-2","0.66-3","0.66-4","0.67-1","0.67-2","0.67-3build0.16.04.1","0.67-3+deb9u1build0.16.04.1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.70-1","0.70-2","0.70-3","0.70-4"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.72-1","0.73-1","0.73-2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.75-3","0.76-1","0.76-2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.78-3","0.79-1","0.80-1","0.80-1build2","0.80-1build3","0.81-1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.83-2","0.83-3"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.83-3build1","0.84-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.83-3","0.83-3build1"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.85-2.1"}]}],"bundled":3},{"source":"osv","ecosystem":"openSUSE:Leap 16.0","package":"putty","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.85-bp160.1.1"}]}],"bundled":3}],"products":[{"vendor":"putty","product":"putty"}],"references":[{"url":"https://lists.tartarus.org/pipermail/putty-announce/2026/000042.html","tags":["Release Notes","report"]},{"url":"https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/ecdsa-remotely-triggerable-assertion.html","tags":["Patch","Vendor Advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48852"},{"url":"https://github.com/advisories/GHSA-rx8r-f2xx-98h9"},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-48852","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-48852","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-48852","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48850","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48851","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-48852","tags":["web"]},{"url":"https://bugzilla.suse.com/1266373","tags":["report"]},{"url":"https://bugzilla.suse.com/1266374","tags":["report"]},{"url":"https://bugzilla.suse.com/1266375","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-48852","description":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","status":"published","published":"2026-05-25T20:19:20.809Z","modified":"2026-05-26T12:39:14.852Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"cna"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T14:19:47.998488Z"}],"euvd":[{"id":"EUVD-2026-31735","description":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","status":"published","published":"2026-05-25T20:19:20Z","modified":"2026-05-26T12:39:14Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T18:21:07.388987Z"}],"ghsa":[{"id":"GHSA-rx8r-f2xx-98h9","title":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","description":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","status":"published","published":"2026-05-26T13:30:51Z","modified":"2026-05-26T13:30:56Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T15:08:17.507995Z"}],"nvd":[{"id":"CVE-2026-48852","description":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","status":"published","published":"2026-05-25T21:16:35.543Z","modified":"2026-07-24T10:10:00.197Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"secondary"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T14:12:20.131508Z"}],"osv":[{"id":"DEBIAN-CVE-2026-48852","description":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","status":"published","published":"2026-05-25T21:16:35.543Z","modified":"2026-10-01T03:03:07.300948638Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T15:45:56.444225Z"},{"id":"UBUNTU-CVE-2026-48852","description":"PuTTY 0.71 before 0.84 has an assertion failure in ECDSA signature verification.","status":"published","published":"2026-05-25T21:16:00Z","modified":"2026-10-17T13:00:24.240226154Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T16:56:33.391918Z"},{"id":"openSUSE-SU-2026:12168-1","title":"putty-0.85-2.1 on GA media","description":"These are all security issues fixed in the putty-0.85-2.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2026-10-17T00:00:00Z","modified":"2026-10-18T11:15:03.244690033Z","updated_at":"2026-11-02T16:58:40.245664Z"},{"id":"openSUSE-SU-2026:22127-1","title":"Security update for putty","description":"This update for putty fixes the following issues:\n\nChanges in putty:\n\n- Update to release 0.85\n\n  * Fixed a remotely triggerable use-after-free in Pageant.\n  * Fixed a remotely triggerable buffer overflow if the OpenSSH\n    encrypt-then-MAC cipher modes are in use. (Only used if a\n    server supports nothing else.)\n  * Fixed a buffer overflow in private key decryption, if the\n    private key is constructed maliciously. (Only triggerable on\n    purpose if you let somebody else generate a key for you.)\n  * Denial-of-service security fixes for where a server could\n    trigger a tight loop in PuTTY, and even a MITM can make it\n    consume unlimited memory at startup.\n\n- Fixed double free in RSA KEX error handling path can be triggered if the key sent by the server is unexpectedly short  [boo#1266375, CVE-2026-48850]\n- Fixed assertion failure in ECDSA signature verification can be triggered during initial key exchange via a crafted host key and signature  [boo#1266373, CVE-2026-48852]\n- Fixed TELNET session data is marked with trust sigils after authenticating to a proxy and allows for password prompt spoofing  [boo#1266374, CVE-2026-48851]\n","status":"published","published":"2026-10-19T16:05:00Z","modified":"2026-10-20T19:15:04.882448721Z","updated_at":"2026-11-02T16:58:42.426393Z"}]}}