{"cve":"CVE-2023-25581","nvd":{"published":"2024-10-10T16:15:04.923","modified":"2026-06-17T05:41:32.250","status":"Deferred","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.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","score":9.2},"cvss_v3":null,"cwes":["CWE-502"],"references":["https://github.com/frohoff/ysoserial","https://github.com/pac4j/pac4j/blob/5834aeb22ad3a4369dfa572be60d7b20f5784a8f/pac4j-core/src/main/java/org/pac4j/core/profile/InternalAttributeHandler.java#L95","https://portswigger.net/web-security/deserialization","https://securitylab.github.com/advisories/GHSL-2022-085_pac4j/"],"products":[],"source":"nvd","synced_at":"2026-10-19T21:55:31.737901711+00:00"},"epss":{"cve":"CVE-2023-25581","score":0.01936,"percentile":0.80069,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-76mw-6p95-x9x5","url":"https://osv.dev/vulnerability/GHSA-76mw-6p95-x9x5","summary":"pac4j-core affected by a Java deserialization vulnerability","modified":"2024-10-14T18:44:38.309922Z","packages":[{"ecosystem":"Maven","name":"org.pac4j:pac4j-core","purl":"pkg:maven/org.pac4j/pac4j-core","ranges":["<4.0.0"],"fixed":["4.0.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}