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Pac4jApplication

CVE-2026-40459

HIGH · 8.8 CVSS v3.1 Published 2026-04-17
Fix available
A fix is available. Upgrade to 4.5.10 / 5.7.10 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
PAC4J is vulnerable to LDAP Injection in multiple methods. A low-privileged remote attacker can inject crafted LDAP syntax into ID-based search parameters, potentially resulting in unauthorized LDAP queries and arbitrary directory operations. This issue was fixed in PAC4J versions 4.5.10, 5.7.10 and 6.4.1

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

PAC4J, a security authentication library for Java, contains an LDAP Injection vulnerability in multiple methods handling ID-based search parameters. Attackers can inject crafted LDAP syntax into these parameters to manipulate LDAP queries, potentially gaining unauthorized access to directory data or performing arbitrary directory operations.

MitigationUpgrade PAC4J to version 4.5.10, 5.7.10, or 6.4.1 (depending on your major version) to obtain the patched code that properly sanitizes LDAP search inputs.

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
Pac4jApplication
Affected:>= 4.0.0, < 4.5.10>= 5.0.0, < 5.7.10>= 6.0.0, < 6.4.1

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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 PAC4J library version
    Inspect your project's dependency management file (Maven pom.xml, Gradle build.gradle) or the pac4j JAR file in your classpath. Look for the pac4j-ldap or pac4j version declaration.
    Affected if The installed version falls within 4.0.0 to 4.5.9, 5.0.0 to 5.7.9, or 6.0.0 to 6.4.0
  2. Confirm LDAP module is in use
    Check your project dependencies for the pac4j-ldap module or equivalent LDAP authentication dependency. Also review your security configuration for LDAP-specific authenticator definitions.
    Affected if The pac4j-ldap module is present and configured as an authentication mechanism
  3. Identify LDAP ID-based search operations
    Review your PAC4J security configuration and application code that uses LdapProfileService, LdapAuthenticator, or similar LDAP-related classes. Look for any method calls that accept ID parameters for directory searches.
    Affected if Your configuration performs LDAP searches using user-provided or derived ID parameters without additional input validation beyond PAC4J's built-in handling

You are affected if your PAC4J version is less than 4.5.10 (v4), 5.7.10 (v5), or 6.4.1 (v6) AND you use the LDAP authentication module with ID-based search operations.

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 4.5.10 / 5.7.10 / 6.4.1 or later
Fixed in 4.5.105.7.106.4.1
Interim mitigation

Upgrade PAC4J to version 4.5.10, 5.7.10, or 6.4.1 (depending on your major version) to obtain the patched code that properly sanitizes LDAP search inputs.

Recommended fix High confidence

4.5.10 (for 4.x users), 5.7.10 (for 5.x users), or 6.4.1 (for 6.x users)

  1. 1. Identify the current Pac4j version in use by checking project dependencies (Maven pom.xml, Gradle build.gradle, or similar)
  2. 2. Determine which major version line is currently deployed (4.x, 5.x, or 6.x)
  3. 3. For projects using Pac4j 4.x: upgrade to version 4.5.10 or later
  4. 4. For projects using Pac4j 5.x: upgrade to version 5.7.10 or later
  5. 5. For projects using Pac4j 6.x: upgrade to version 6.4.1 or later
  6. 6. Update the dependency in build configuration file
  7. 7. Rebuild and redeploy the application
  8. 8. Test LDAP authentication functionality to verify the upgrade does not break existing workflows
Caveat Minor version upgrades within the same major version typically have backward compatibility; review release notes if skipping multiple minor versions

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

Fix this in Pac4j Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
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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-2026-40459 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
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