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.
References7
- github.com/networknt/light-4j/blob/2.3.7/basic-auth/src/main/ja…
- github.com/networknt/light-4j/blob/2.3.7/ldap-util/src/main/jav…
- github.com/networknt/light-4j/commit/54743badb34260b76ed131d8b6…
- github.com/networknt/light-4j/issues/2804
- github.com/networknt/light-4j/pull/2805
- github.com/networknt/light-4j/releases/tag/2.4.0
- www.vulncheck.com/advisories/networknt-light-4j-2.1.5-before-2.…
Metrics
- CVSS 3.1
-
7.4
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS 4.0
-
9.1
CRITICAL
Score source: CNA
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 - EPSS — exploit probability
- 1% percentile: 47 · as of 9 November 2026
- CWE
- CWE-287
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.