Skip to main content
Live Webinar with SANS (June 25)— Agentic CTI Automation for Fun & ProfitRegister Free
Mallory
Unrated

LDAP DN Injection in Apache Shiro DefaultLdapRealm

IdentifiersCVE-2026-49268CWE-90

CVE-2026-49268 is a remote LDAP distinguished name (DN) injection vulnerability in Apache Shiro's DefaultLdapRealm. The flaw is caused by directly concatenating user-supplied username input into the LDAP DN template used for bind authentication without escaping RFC 2253 special characters. Because the DN is constructed from untrusted input, an attacker can inject LDAP special characters and alter the resulting DN structure used during authentication. According to the provided content, this can enable authentication bypass and impersonation of other users. The issue affects Apache Shiro versions through 2.2.0 and 3.0.0-alpha-0 through 3.0.0-alpha-1 when DefaultLdapRealm is used.

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can let a remote attacker manipulate the LDAP bind DN used by DefaultLdapRealm, potentially bypassing authentication checks or authenticating as another user by impersonating a legitimate identity. This undermines the integrity of LDAP-backed authentication and can result in unauthorized access to applications protected by Apache Shiro.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, avoid using DefaultLdapRealm with untrusted username input. Apply strict validation and RFC 2253-compliant escaping of username values before constructing LDAP distinguished names, and reduce exposure of LDAP-backed authentication endpoints until the upgrade can be completed.

Remediation

Patch, then assume compromise.

Upgrade Apache Shiro to a fixed release: 2.2.1 or 3.0.0-alpha-2 or later. The provided content indicates these versions correct the DN construction issue. Applications using DefaultLdapRealm should also ensure username input is properly escaped before being incorporated into LDAP distinguished names.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Apache Software FoundationShiroapplication
Apache Software FoundationShiro-Coreapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity6

Community discussion across Reddit, Mastodon, and other social sources.