{"id":"CVE-2026-113682","kind":"vulnerability","aliases":["CVE-2026-113682"],"related":[],"title":"light-4j: empty-password Basic auth lets attackers log in as LDAP users","description":"Networknt light-4j from 2.1.5 before 2.4.0 contains an authentication bypass vulnerability in BasicAuthHandler that allows unauthenticated attackers to log in as LDAP/AD-delegated users. Attackers can send a Basic Authorization header with a known username and empty password, triggering an unauthenticated LDAP bind that is accepted as successful authentication.","summary":"light-4j is a Java microservices framework whose BasicAuthHandler accepts an LDAP bind with an empty password as a successful login. An unauthenticated attacker who knows a username can send a Basic Authorization header with an empty password and be logged in as that LDAP or Active Directory user.","severity":"critical","cvss":9.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["active-directory","java","ldap","light-4j","microservices","package"],"not_affected_if":["basic-auth-not-used","no-ldap-auth","versions-outside-2.1.5-to-2.4.0"],"how_to_check":"Check the light-4j version in the project's pom.xml or build.gradle; affected versions are 2.1.5 up to but not including 2.4.0.","fix":"Upgrade light-4j to 2.4.0 or later.","status":"open","published_at":"2026-10-20T16:17:13+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","triaged_at":"2026-10-23T22:39:28+00:00","updated_at":"2026-10-23T22:39:28+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-23T22:39:28Z","model":"claude-haiku-5-5","output":{"fix":"Upgrade light-4j to 2.4.0 or later.\nunknown","reach":"internet","title":"light-4j: empty-password Basic auth lets attackers log in as LDAP users","impact":"high","summary":"light-4j is a Java microservices framework whose BasicAuthHandler accepts an LDAP bind with an empty password as a successful login. An unauthenticated attacker who knows a username can send a Basic Authorization header with an empty password and be logged in as that LDAP or Active Directory user.","category":"package","who_cares":["java","light-4j","ldap","active-directory","microservices"],"confidence":0.8,"needs_auth":"no","worst_case":"Attacker logs in as any known LDAP user without a password.","analyst_note":"Confirm the exact fixed-version behavior and whether BasicAuthHandler is used with LDAP in default configs; check the NVD entry for a how-to-check and workaround.","how_to_check":"Check the light-4j version in the project's pom.xml or build.gradle; affected versions are 2.1.5 up to but not including 2.4.0.\nunknown","needs_analyst":true,"not_affected_if":["no-ldap-auth","basic-auth-not-used","versions-outside-2.1.5-to-2.4.0"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"critical"},"cost_usd":0.000535,"input_tokens":2973,"output_tokens":475,"severity_before":"critical"},"analyst_status":null,"analyst_note":null,"search":"'-113682':18A,21A '-2026':17A,20A '2.1.5':87C '2.4.0':89C '4j':3A,29B,34B,85C 'accept':42B,128C 'activ':23B,79B 'active-directori':22B 'allow':98C 'attack':10A,56B,100C,107C 'auth':8A 'authent':92C,131C 'author':65B,112C 'basic':7A,64B,111C 'basicauthhandl':41B,96C 'bind':45B,125C 'bypass':93C 'contain':90C 'cve':16A,19A 'directori':24B,80B 'empti':5A,48B,69B,119C 'empty-password':4A 'framework':39B 'header':66B,113C 'java':25B,37B 'know':58B 'known':116C 'ldap':14A,26B,44B,77B,124C 'ldap/ad-delegated':105C 'let':9A 'light':2A,28B,33B,84C 'light-4j':1A,27B,32B,83C 'log':11A,73B,102C 'login':53B 'microservic':30B,38B 'networknt':82C 'packag':31B 'password':6A,49B,70B,120C 'send':62B,109C 'success':52B,130C 'trigger':121C 'unauthent':55B,99C,123C 'user':15A,81B,106C 'usernam':60B,117C 'vulner':94C 'whose':40B","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T16:17:13+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/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-2026-113682","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-113682","severity":null,"published_at":"2026-10-20T16:17:13+00:00","modified_at":"2026-10-23T14:17:32+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","fetched_at":"2026-10-23T22:28:58+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"}