CVE-2026-40458 json
Cross-Site Request Forgery in PAC4J
published 6mo ago modified last mo. also GHSA-xw5c-jc7x-gf75 , EUVD-2026-23421
- cvss
- 6.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 5%
- public exploits
- 0
- none known
Summary
PAC4J is vulnerable to Cross-Site Request Forgery (CSRF). A malicious attacker can craft a specially designed website which, when visited by a user, will automatically submit a forged cross-site request with a token whose hash collides with the victim's legitimate CSRF token. Importantly, the attacker does not need to know the victim’s CSRF token or its hash prior to the attack. Collisions in the deterministic String.hashCode() function can be computed directly, reducing the effective token's security space to 32 bits. This bypasses CSRF protection, allowing profile updates, password changes, account linking, and any other state-changing operations to be performed without the victim's consent.
This issue was fixed in PAC4J versions 5.7.10 and 6.4.1
Patch / fix
- maven org.pac4j:pac4j-core 5.7.10, 6.4.1
- PAC4J PAC4J 5.7.10, 6.4.1
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6mo ago
Exploit prediction
0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N |
| CNA | 4.0 | 7.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
| GitHub | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | org.pac4j:pac4j-core | <5.7.10 >=6.0.0-RC1, <6.4.1 |
5.7.10 6.4.1 |
Affected products
- PAC4J PAC4J
Classification
- Weakness
-
- CWE-352 Cross-Site Request Forgery
References
-
pac4j.org
/blog/security-advisory-pac4j-core-and-ldap.html
vendor-advisory, web
-
cert.pl
/en/posts/2026/04/CVE-2026-40458/
third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-40458
advisory
-
cert.pl
/en/posts/2026/04/CVE-2026-40458
web
-
github.com
/pac4j/pac4j
package
Sources
- CVE List CVE-2026-40458
- GitHub Advisory GHSA-xw5c-jc7x-gf75
- NVD CVE-2026-40458
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