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ShiroApplication · Apache

CVE-2026-49268

CRITICAL · 9.1 CVSS v3.1 Published 2026-06-17
Fix available
A fix is available. Upgrade to 2.2.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

DefaultLdapRealm in Apache Shiro versions through 2.2.0 and 3.0.0-alpha-1 directly concatenates user-supplied usernames into LDAP DN templates without RFC 2253 special character escaping, allowing LDAP injection that can manipulate the DN structure for authentication bypass or user impersonation.

MitigationUpgrade to Apache Shiro 2.2.1 or 3.0.0-alpha-2 or later to apply the fixed DN escaping logic.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ShiroApplication
Affected:< 2.2.1= 3.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Apache Shiro version
    Locate the shiro-core JAR file in your classpath or check your pom.xml/gradle build file for the org.apache.shiro:shiro-core dependency version
    Affected if The version is below 2.2.1 or exactly 3.0.0-alpha-1
  2. Confirm DefaultLdapRealm is in use
    Search your codebase for 'DefaultLdapRealm' or 'LdapRealm' class references in your Shiro configuration files (shiro.ini, Spring beans, or Java config classes)
    Affected if DefaultLdapRealm is configured as the LDAP authentication realm
  3. Verify LDAP DN template configuration
    Inspect your LDAP realm configuration for the 'userDnTemplate' property or similar DN template settings that incorporate usernames directly into the DN pattern
    Affected if A userDnTemplate is configured (e.g., 'uid={0},ou=users,dc=example,dc=com')
  4. Inspect username handling before LDAP bind
    Review code that passes username to the LDAP realm's authenticate method or searches for any custom escaping/sanitization logic applied to usernames before LDAP operations
    Affected if Usernames are passed directly to LDAP without RFC 2253 escaping (no use of LdapUtils.escapeLdapDN or similar escaping methods)

You are affected if you run Apache Shiro version below 2.2.1 or exactly 3.0.0-alpha-1, use DefaultLdapRealm with a configured userDnTemplate, and user-supplied usernames reach the LDAP authentication without proper RFC 2253 DN character escaping.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.2.1 or later
Fixed in 2.2.1
Interim mitigation

Upgrade to Apache Shiro 2.2.1 or 3.0.0-alpha-2 or later to apply the fixed DN escaping logic.

Recommended fix High confidence

Apache Shiro 2.2.1 (stable) or 3.0.0-alpha-2

  1. 1. Identify all dependencies on Apache Shiro in your project using your build tool (Maven pom.xml, Gradle build.gradle, etc.)
  2. 2. Locate the current Apache Shiro version in your dependency management
  3. 3. If using Shiro 2.x: Update the Shiro version to 2.2.1 or later
  4. 4. If using Shiro 3.0.0-alpha-1: Update to 3.0.0-alpha-2 or later
  5. 5. Rebuild your project to fetch the updated dependencies
  6. 6. Run your test suite to verify the application still functions correctly after the upgrade
  7. 7. Specifically test any LDAP authentication flows to confirm the fix works as expected

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Shiro Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,540
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-49268 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data