CVE-2026-49268

EUVD-2026-37701

17.06.2026, 14:17

A remote attacker can inject LDAP special characters into the Distinguished Name (DN) construction in DefaultLdapRealm class. User-supplied username input is directly concatenated into the LDAP DN template without any escaping of RFC 2253 special characters. This allows an attacker to manipulate the DN structure used for LDAP bind authentication, potentially bypassing authentication or impersonating other users.

This issue affects all Apache Shiro versions through 2.2.0, and 3.0.0-alpha-1 when using DefaultLdapRealm
Upgrade to Apache Shiro 2.2.1 or 3.0.0-alpha-2 or later, which fixes the issue.

LDAP Injection

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	9.1 CRITICAL	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Base Score

CVSS 3.x

EPSS Score

Percentile: 41.05%

Affected Products (NVD)

Vendor	Product	Version
apache	shiro	𝑥 < 2.2.1
apache	shiro	3.0.0:alpha1

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

shiro

bookworm	vulnerable
sid	vulnerable
trixie	no-dsa

Ubuntu Releases

Ubuntu Product

Codename

shiro

bionic	needs-triage
focal	needs-triage
jammy	needs-triage
noble	needs-triage
questing	ignored
resolute	needs-triage
xenial	needs-triage

Common Weakness Enumeration

CWE-90 - Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
The software constructs all or part of an LDAP query using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended LDAP query when it is sent to a downstream component.

References

https://lists.apache.org/thread/svszql3od8td7hn6conyj2oq70v53b5s

http://www.openwall.com/lists/oss-security/2026/06/17/8