{"id":"CVE-2026-16920","kind":"vulnerability","aliases":["CVE-2026-16920"],"related":[],"title":"IBM API Connect V12 OnPrem: logged-in user can bypass security restrictions via confused deputy flaw (fixed in 12.1.1.3)","description":"IBM API Connect 12.1.0.0 through 12.1.1.2 could allow a remote authenticated attacker to bypass security restrictions due to a confused deputy vulnerability.","summary":"IBM says API Connect V12 OnPrem v12.1.0.0 through v12.1.1.2 could let a remote authenticated attacker bypass security restrictions due to a confused deputy flaw (CWE-441, unintended proxy or intermediary). IBM rated it CVSS 9.9 with changed scope. IBM does not say which restrictions are bypassed.","severity":"critical","cvss":9.9,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"api-connect-v12-onprem","fixed":["12.1.1.3"],"affected":">= 12.1.0.0, <= 12.1.1.2","ecosystem":"vendor"}],"ecosystems":[],"tags":["api-gateway","auth-required","ibm-api-connect","infrastructure","self-hosted"],"not_affected_if":["outside-affected-versions","unaffected-version","version-outside-range"],"how_to_check":"Check your API Connect V12 OnPrem version. Affected per IBM: v12.1.0.0 - v12.1.1.2. Fixed: v12.1.1.3. A valid account is required. IBM's bulletin lists only V12 OnPrem for this CVE; if you run 10.0.8.x, IBM does not list it here.","fix":"Upgrade to v12.1.1.3 via IBM Fix Central (https://www.ibm.com/support/pages/node/7290205). IBM lists no workarounds or mitigations.","status":"open","published_at":"2026-11-07T05:18:22+00:00","first_seen_at":"2026-11-07T05:45:58+00:00","triaged_at":"2026-11-07T05:48:16+00:00","updated_at":"2026-11-07T06:01:26+00:00","category":"infrastructure","confidence":0.85,"triage":{"at":"2026-11-07T05:48:16Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"IBM API Connect: authenticated users can bypass security restrictions remotely","impact":"high","summary":"IBM API Connect versions 12.1.0.0 through 12.1.1.2 contain a confused deputy flaw that lets a remote, logged-in attacker bypass security restrictions. The NVD entry rates it critical (CVSS 9.9), but the description does not say what protected data or actions are reached.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["ibm-api-connect","api-gateway","self-hosted"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"Authenticated attacker bypasses security restrictions on the API platform","analyst_note":"Find IBM's security bulletin for CVE-2026-16920 to confirm the fixed version and the exact restrictions bypassed.","how_to_check":"- Confirm whether an IBM API Connect instance is deployed and note its version.\n- Check the installed version against the affected range `12.1.0.0` through `12.1.1.2`.","plain_action":"","needs_analyst":true,"not_affected_if":["version-outside-range"],"who_is_affected":"Organizations running IBM API Connect 12.1.0.0 through 12.1.1.2 where users hold accounts on the platform. The sources do not describe the specific configuration or role that makes an installation exposed, so whether a given deployment is affected beyond the version range is unknown.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.000699,"input_tokens":4195,"output_tokens":558,"severity_before":"critical"},"analyst_status":"done","analyst_note":"Find IBM's security bulletin for CVE-2026-16920 to confirm the fixed version and the exact restrictions bypassed.","search":"'-16920':23A,26A '-2026':22A,25A '-441':71B '12.1.0.0':95C '12.1.1.2':97C '12.1.1.3':20A '9.9':80B 'allow':99C 'api':2A,28A,33B,40B,48B,93C 'api-connect-v12-onprem':27A 'api-gateway':32B 'attack':60B,103C 'auth':36B 'auth-requir':35B 'authent':59B,102C 'bypass':11A,61B,91B,105C 'chang':82B 'confus':15A,67B,111C 'connect':3A,29A,41B,49B,94C 'could':55B,98C 'cve':21A,24A 'cvss':79B 'cwe':70B 'deputi':16A,68B,112C 'due':64B,108C 'fix':18A 'flaw':17A,69B 'gateway':34B 'host':45B 'ibm':1A,39B,46B,76B,84B,92C 'ibm-api-connect':38B 'infrastructur':42B 'intermediari':75B 'let':56B 'log':7A 'logged-in':6A 'onprem':5A,31A,51B 'proxi':73B 'rate':77B 'remot':58B,101C 'requir':37B 'restrict':13A,63B,89B,107C 'say':47B,87B 'scope':83B 'secur':12A,62B,106C 'self':44B 'self-host':43B 'unintend':72B 'user':9A 'v12':4A,30A,50B 'v12.1.0.0':52B 'v12.1.1.2':54B 'via':14A 'vulner':113C","nicknames":[],"mitigations":[],"who_affected":"Teams running self-managed IBM API Connect V12 OnPrem v12.1.0.0 to v12.1.1.2. Any authenticated user may be able to bypass security restrictions through a confused deputy flaw (CVSS 9.9, changed scope); IBM does not say which restrictions. Teams on v12.1.1.3 or later, and those not running V12 OnPrem, can skip it.","tier":"B","verified":{"fix":{"at":"2026-11-07T06:01:26Z","by":"analyst","doc":"https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39","run_id":1996},"products":{"at":"2026-11-07T06:01:26Z","by":"analyst","doc":"https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39","run_id":1996},"workarounds":{"at":"2026-11-07T06:01:26Z","by":"analyst","doc":"https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39","run_id":1996},"how_to_check":{"at":"2026-11-07T06:01:26Z","by":"analyst","doc":"https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39","run_id":1996},"who_affected":{"at":"2026-11-07T06:01:26Z","by":"analyst","doc":"https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39","run_id":1996}},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":["apiconnectv12onprem"],"ptokens":["api","connect","onprem","v12"],"labels":["apigateway","authrequired","critical","ibmapiconnect","infrastructure","selfhosted"],"campaign_type":null,"search_a":"'-16920':23A,26A '-2026':22A,25A '12.1.1.3':20A 'api':2A,28A 'api-connect-v12-onprem':27A 'bypass':11A 'confus':15A 'connect':3A,29A 'cve':21A,24A 'deputi':16A 'fix':18A 'flaw':17A 'ibm':1A 'log':7A 'logged-in':6A 'onprem':5A,31A 'restrict':13A 'secur':12A 'user':9A 'v12':4A,30A 'via':14A","search_b":"'-441':71B '9.9':80B 'api':33B,40B,48B 'api-gateway':32B 'attack':60B 'auth':36B 'auth-requir':35B 'authent':59B 'bypass':61B,91B 'chang':82B 'confus':67B 'connect':41B,49B 'could':55B 'cvss':79B 'cwe':70B 'deputi':68B 'due':64B 'flaw':69B 'gateway':34B 'host':45B 'ibm':39B,46B,76B,84B 'ibm-api-connect':38B 'infrastructur':42B 'intermediari':75B 'let':56B 'onprem':51B 'proxi':73B 'rate':77B 'remot':58B 'requir':37B 'restrict':63B,89B 'say':47B,87B 'scope':83B 'secur':62B 'self':44B 'self-host':43B 'unintend':72B 'v12':50B 'v12.1.0.0':52B 'v12.1.1.2':54B","search_c":"'12.1.0.0':95C '12.1.1.2':97C 'allow':99C 'api':93C 'attack':103C 'authent':102C 'bypass':105C 'confus':111C 'connect':94C 'could':98C 'deputi':112C 'due':108C 'ibm':92C 'remot':101C 'restrict':107C 'secur':106C 'vulner':113C","first_public_at":"2026-11-07T05:18:22+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cvss_by":"psirt@us.ibm.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-16920","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-16920","severity":null,"published_at":"2026-11-07T05:18:22+00:00","modified_at":"2026-11-07T05:18:23+00:00","first_seen_at":"2026-11-07T05:45:58+00:00","fetched_at":"2026-11-07T05:45:58+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-16920:1996","url":"https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39","severity":null,"published_at":"2026-11-07T06:01:26+00:00","modified_at":"2026-11-07T06:01:26+00:00","first_seen_at":"2026-11-07T06:01:26+00:00","fetched_at":"2026-11-07T06:01:26+00:00","note":"Read IBM bulletin -39 (v12.1.1.3): CVE-2026-16920 CWE-441, CVSS 9.9, V12 OnPrem v12.1.0.0-v12.1.1.2, fix v12.1.1.3, workarounds None. Exact restrictions bypassed not stated by IBM. No exploitation/PoC or social search done.","cites":["https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39"]}],"documents":[{"id":93149,"url":"https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39","title":"IBM Security Bulletin: Multiple Vulnerabilities in IBM API Connect (v12.1.1.3)","kind":"advisory","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"advisory","confidence":null,"note":null}],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}