{"id":"CVE-2026-119561","kind":"vulnerability","aliases":["CVE-2026-119561"],"related":[],"title":"phpMyAdmin: WebAuthn check skips signature verification, letting attackers bypass second factor","description":"phpMyAdmin through 5.2.3 contains an authentication bypass vulnerability in CustomServer::parseAndValidateAssertionResponse() that never verifies WebAuthn assertion signatures against stored public keys. Attackers holding a victim's MySQL credentials can POST a crafted webauthn_request_response with matching challenge, origin, and rpIdHash to bypass the second factor and gain database privileges.","summary":"phpMyAdmin through 5.2.3 does not check WebAuthn assertion signatures against stored public keys during login. An attacker who already holds a victim's MySQL credentials can submit a crafted response to skip the second factor and gain database privileges.","severity":"high","cvss":7.6,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["mysql","package","php","phpmyadmin","webauthn"],"not_affected_if":["newer-version","no-webauthn-2fa"],"how_to_check":"- Check the installed phpMyAdmin version and whether it is `5.2.3` or earlier.\n- Check whether WebAuthn or security-key two-factor login is enabled in the phpMyAdmin configuration.","fix":"- Move to a phpMyAdmin release later than `5.2.3`; the sources do not name the fixed version.","status":"open","published_at":"2026-10-30T12:16:43+00:00","first_seen_at":"2026-10-30T12:30:26+00:00","triaged_at":"2026-10-30T12:32:19+00:00","updated_at":"2026-10-30T12:32:19+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-30T12:32:19Z","model":"claude-haiku-5-5","output":{"fix":"- Move to a phpMyAdmin release later than `5.2.3`; the sources do not name the fixed version.","reach":"internet","title":"phpMyAdmin: WebAuthn check skips signature verification, letting attackers bypass second factor","impact":"high","summary":"phpMyAdmin through 5.2.3 does not check WebAuthn assertion signatures against stored public keys during login. An attacker who already holds a victim's MySQL credentials can submit a crafted response to skip the second factor and gain database privileges.","audience":"businesses","category":"package","nicknames":[],"who_cares":["phpmyadmin","mysql","php","webauthn"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"Attacker gains database privileges after bypassing second-factor login","analyst_note":"Confirm the fixed phpMyAdmin version and whether WebAuthn 2FA is off by default; the NVD entry alone does not give either.","how_to_check":"- Check the installed phpMyAdmin version and whether it is `5.2.3` or earlier.\n- Check whether WebAuthn or security-key two-factor login is enabled in the phpMyAdmin configuration.","plain_action":"","needs_analyst":true,"not_affected_if":["no-webauthn-2fa","newer-version"],"who_is_affected":"Teams that run phpMyAdmin 5.2.3 or earlier with WebAuthn two-factor login enabled are exposed, since the flaw sits in the second-factor check. Attackers must already have a valid MySQL username and password, so installations without WebAuthn 2FA are less exposed. Sources do not state whether default configurations enable WebAuthn.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000729,"input_tokens":4160,"output_tokens":626,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-119561':14A,17A '-2026':13A,16A '5.2.3':25B,64C 'alreadi':41B 'assert':30B,77C 'attack':8A,39B,83C 'authent':67C 'bypass':9A,68C,104C 'challeng':99C 'check':3A,28B 'contain':65C 'craft':51B,93C 'credenti':47B,89C 'customserv':71C 'cve':12A,15A 'databas':60B,110C 'factor':11A,57B,107C 'gain':59B,109C 'hold':42B,84C 'key':35B,82C 'let':7A 'login':37B 'match':98C 'mysql':18B,46B,88C 'never':74C 'origin':100C 'packag':19B 'parseandvalidateassertionrespons':72C 'php':20B 'phpmyadmin':1A,21B,23B,62C 'post':91C 'privileg':61B,111C 'public':34B,81C 'request':95C 'respons':52B,96C 'rpidhash':102C 'second':10A,56B,106C 'signatur':5A,31B,78C 'skip':4A,54B 'store':33B,80C 'submit':49B 'verif':6A 'verifi':75C 'victim':44B,86C 'vulner':69C 'webauthn':2A,22B,29B,76C,94C","nicknames":[],"mitigations":[],"who_affected":"Teams that run phpMyAdmin 5.2.3 or earlier with WebAuthn two-factor login enabled are exposed, since the flaw sits in the second-factor check. Attackers must already have a valid MySQL username and password, so installations without WebAuthn 2FA are less exposed. Sources do not state whether default configurations enable WebAuthn.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"businesses","plain_action":null,"first_public_at":"2026-10-30T12:16:43+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/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-2026-119561","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119561","severity":null,"published_at":"2026-10-30T12:16:43+00:00","modified_at":"2026-10-30T12:16:43+00:00","first_seen_at":"2026-10-30T12:30:26+00:00","fetched_at":"2026-10-30T12:30:26+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}