{"id":"CVE-2026-129116","kind":"vulnerability","aliases":["CVE-2026-129116"],"related":[],"title":"C-Kermit: IKSD SSL build lets refused certificate logins bypass authentication","description":"C-Kermit from 7.0.197 before 11.1.515 contains an authentication bypass vulnerability in the IKSD SSL build that leaves Telnet authentication state at AUTH_VALID after a refused certificate login. Attackers holding a trusted certificate mapped to a refused account can log in as any other account with any password, gaining that account's shell access.","summary":"C-Kermit's IKSD server in its SSL build leaves Telnet authentication marked valid after a certificate login is refused. An attacker holding a trusted certificate mapped to a refused account can log in as any other account with any password and get that account's shell.","severity":"high","cvss":7.7,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["c-kermit","iksd","runtime","self-hosted","telnet"],"not_affected_if":["certificate-login-disabled","iksd-not-running","no-ssl-build"],"how_to_check":"- Check the installed C-Kermit version with `kermit -v` or the package manager; affected range is `7.0.197` before `11.1.515`.\n- Check whether IKSD is running with SSL enabled and whether it accepts certificate logins (unknown for default config).","fix":"- C-Kermit: move to `11.1.515` or later (per the product ranges).","status":"open","published_at":"2026-11-13T17:17:28+00:00","first_seen_at":"2026-11-13T17:48:00+00:00","triaged_at":"2026-11-13T17:48:50+00:00","updated_at":"2026-11-13T17:48:50+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-11-13T17:48:50Z","model":"claude-haiku-5-5","output":{"fix":"- C-Kermit: move to `11.1.515` or later (per the product ranges).","reach":"network","title":"C-Kermit: IKSD SSL build lets refused certificate logins bypass authentication","impact":"high","summary":"C-Kermit's IKSD server in its SSL build leaves Telnet authentication marked valid after a certificate login is refused. An attacker holding a trusted certificate mapped to a refused account can log in as any other account with any password and get that account's shell.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["c-kermit","iksd","self-hosted","telnet"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"attacker gets shell access as any other account on the server","analyst_note":"Confirm the default config of the IKSD SSL build and whether the vendor advisory names a specific setting to disable; check the NVD and vulncheck pages for exploit status.","how_to_check":"- Check the installed C-Kermit version with `kermit -v` or the package manager; affected range is `7.0.197` before `11.1.515`.\n- Check whether IKSD is running with SSL enabled and whether it accepts certificate logins (unknown for default config).","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["iksd-not-running","no-ssl-build","certificate-login-disabled"],"who_is_affected":"Only servers running C-Kermit's IKSD in the SSL build, where certificate-based login is accepted. An attacker needs a trusted client certificate mapped to some account; systems without IKSD SSL or without certificate login are not exposed. Sources do not say how widely the SSL build is deployed.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000782,"input_tokens":4647,"output_tokens":635,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-129116':15A,18A '-2026':14A,17A '11.1.515':82C '7.0.197':80C 'access':131C 'account':59B,66B,73B,115C,122C,128C 'attack':50B,106C 'auth':99C 'authent':12A,40B,85C,96C 'build':6A,37B,92C 'bypass':11A,86C 'c':2A,20B,29B,77C 'c-kermit':1A,19B,28B,76C 'certif':9A,45B,54B,104C,110C 'contain':83C 'cve':13A,16A 'gain':126C 'get':71B 'hold':51B,107C 'host':26B 'iksd':4A,22B,32B,90C 'kermit':3A,21B,30B,78C 'leav':38B,94C 'let':7A 'log':61B,117C 'login':10A,46B,105C 'map':55B,111C 'mark':41B 'password':69B,125C 'refus':8A,48B,58B,103C,114C 'runtim':23B 'self':25B 'self-host':24B 'server':33B 'shell':75B,130C 'ssl':5A,36B,91C 'state':97C 'telnet':27B,39B,95C 'trust':53B,109C 'valid':42B,100C 'vulner':87C","nicknames":[],"mitigations":[],"who_affected":"Only servers running C-Kermit's IKSD in the SSL build, where certificate-based login is accepted. An attacker needs a trusted client certificate mapped to some account; systems without IKSD SSL or without certificate login are not exposed. Sources do not say how widely the SSL build is deployed.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ckermit","high","iksd","runtime","selfhosted","telnet"],"campaign_type":null,"search_a":"'-129116':15A,18A '-2026':14A,17A 'authent':12A 'build':6A 'bypass':11A 'c':2A 'c-kermit':1A 'certif':9A 'cve':13A,16A 'iksd':4A 'kermit':3A 'let':7A 'login':10A 'refus':8A 'ssl':5A","search_b":"'account':59B,66B,73B 'attack':50B 'authent':40B 'build':37B 'c':20B,29B 'c-kermit':19B,28B 'certif':45B,54B 'get':71B 'hold':51B 'host':26B 'iksd':22B,32B 'kermit':21B,30B 'leav':38B 'log':61B 'login':46B 'map':55B 'mark':41B 'password':69B 'refus':48B,58B 'runtim':23B 'self':25B 'self-host':24B 'server':33B 'shell':75B 'ssl':36B 'telnet':27B,39B 'trust':53B 'valid':42B","search_c":"'11.1.515':82C '7.0.197':80C 'access':131C 'account':115C,122C,128C 'attack':106C 'auth':99C 'authent':85C,96C 'build':92C 'bypass':86C 'c':77C 'c-kermit':76C 'certif':104C,110C 'contain':83C 'gain':126C 'hold':107C 'iksd':90C 'kermit':78C 'leav':94C 'log':117C 'login':105C 'map':111C 'password':125C 'refus':103C,114C 'shell':130C 'ssl':91C 'state':97C 'telnet':95C 'trust':109C 'valid':100C 'vulner':87C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-10-31T01:36:55+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/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","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-129116","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-129116","severity":null,"published_at":"2026-11-13T17:17:28+00:00","modified_at":"2026-11-13T17:17:28+00:00","first_seen_at":"2026-11-13T17:48:00+00:00","fetched_at":"2026-11-13T17:48:00+00:00","note":null}],"documents":[{"id":148075,"url":"https://github.com/OpenKermit/ckermit/commit/fdfe8f13159f9276d87e02bedba15946b0edda97","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":148076,"url":"https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":148077,"url":"https://github.com/OpenKermit/ckermit/security/advisories/GHSA-5pc4-gh6q-5h4w","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-31T01:36:55+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":148078,"url":"https://www.vulncheck.com/advisories/c-kermit-7.0.197-before-11.1.515-iksd-authentication-bypass-via-refused-certificate-login","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}