Medium (6.5). EPSS 0.6% chance of exploitation in the next 30 days.
Lemonldap::NG::Handler versions from 2.0.0 before 2.16.10, from 2.17.0 before 2.21.6, from 2.22.0 before 2.23.4 for Perl allow an equivalent spelling of a path to bypass the locationRules that restrict it.
The handler matches each vhost's locationRules regular expressions against REQUEST_URI, the raw request line, while the web server routes on the path it has already percent-decoded and normalized. A request that percent-encodes a character of the path, inserts dot segments, or doubles a slash therefore reaches the protected resource under a URI that no rule regexp matches, and the vhost's default rule decides access. Deny rules, identity and group conditions, and unprotect and skip rules are bypassed alike.
Only a vhost whose default rule is more permissive than its other rules is affected. An authenticated user then reaches any URL a locationRules regexp was meant to restrict, but gains no more than that default rule already grants.
Severity
CVSS 3.1
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS
0.6% chance of exploitation in the next 30 days; higher than 46% of CVEs (scores of 2026-10-31)