CVE-2026-40459: pac4j — Fix

Description

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

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CVSS v3.1 Score

8.8

HIGH

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

EPSS — Exploit Prediction

0.0014

Probability of exploitation

0.34%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-90 CWE-90

Affected Products

Vendor	Product	Versions
pac4j	pac4j	4.0.0 — 4.5.10
pac4j	pac4j	5.0.0 — 5.7.10
pac4j	pac4j	6.0.0 — 6.4.1

References

Advisories & Patches

https://www.pac4j.org/blog/security-advisory-pac4j-core-and-ldap.html

Other References

https://cert.pl/en/posts/2026/04/CVE-2026-40458/

Frequently Asked Questions

What is CVE-2026-40459? +

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 It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-40459? +

CVE-2026-40459 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0014, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-40459? +

CVE-2026-40459 affects products from pac4j, specifically: pac4j. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-40459? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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