How severe is CVE-2023-25581?

CVE-2023-25581 has a CVSS 4.0 base score of 9.2, rated critical severity.

Is CVE-2023-25581 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2023-25581?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2023-25581 have an EU (EUVD) identifier?

Yes. CVE-2023-25581 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-2974.

When was CVE-2023-25581 published?

CVE-2023-25581 was published on 2024-10-10 and last updated on 2026-06-17.

CVE-2023-25581

CVE-2023-25581 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 4.0 base score 9.2)
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-2974
Weakness: CWE-502
Published: 2024-10-10
Last modified: 2026-06-17

Description

pac4j is a security framework for Java. `pac4j-core` prior to version 4.0.0 is affected by a Java deserialization vulnerability. The vulnerability affects systems that store externally controlled values in attributes of the `UserProfile` class from pac4j-core. It can be exploited by providing an attribute that contains a serialized Java object with a special prefix `{#sb64}` and Base64 encoding. This issue may lead to Remote Code Execution (RCE) in the worst case. Although a `RestrictedObjectInputStream` is in place, that puts some restriction on what classes can be deserialized, it still allows a broad range of java packages and potentially exploitable with different gadget chains. pac4j versions 4.0.0 and greater are not affected by this issue. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Frequently asked questions

What is CVE-2023-25581?: pac4j is a security framework for Java. `pac4j-core` prior to version 4.0.0 is affected by a Java deserialization vulnerability. The vulnerability affects systems that store externally controlled values in attributes of the `UserProfile` class from pac4j-core. It can be exploited by providing an attribute that contains a serialized Java object with a special prefix `{#sb64}` and Base64 encoding. This issue may lead to Remote Code Execution (RCE) in the worst case. Although a `RestrictedObjectInputStream` is in place, that puts some restriction on what classes can be deserialized, it still allows a broad range of java packages and potentially exploitable with different gadget chains. pac4j versions 4.0.0 and greater are not affected by this issue. Users are advised to upgrade. There are no known workarounds for this vulnerability.
How severe is CVE-2023-25581?: CVE-2023-25581 has a CVSS 4.0 base score of 9.2, rated critical severity.
Is CVE-2023-25581 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2023-25581?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2023-25581 have an EU (EUVD) identifier?: Yes. CVE-2023-25581 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-2974.
When was CVE-2023-25581 published?: CVE-2023-25581 was published on 2024-10-10 and last updated on 2026-06-17.

References

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