CVE-2025-31129 is a high-severity (CVSS 8.8) Deserialization of Untrusted Data vulnerability in io.jooby:jooby-pac4j. A fix is available for io.jooby:jooby-pac4j — see the affected versions and patch details below.
jooby-pac4j: deserialization of untrusted data
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-31129.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-31129 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
io.jooby:jooby-pac4j☕io.jooby:jooby-pac4jReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Jooby is a web framework for Java and Kotlin. The pac4j io.jooby.internal.pac4j.SessionStoreImpl#get module deserializes untrusted data. This vulnerability is fixed in 2.17.0 (2.x) and 3.7.0 (3.x).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.jooby:jooby-pac4j | all versions | 2.17.0io.jooby:jooby-pac4j:2.17.0 |
| ☕Maven | io.jooby:jooby-pac4j | ≥ 3.0.0.M1&&< 3.7.0 | 3.7.0io.jooby:jooby-pac4j:3.7.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.jooby:jooby-pac4j, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.jooby:jooby-pac4j to 2.17.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-31129 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-31129 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-31129. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-31129 in your dependencies?
O3 Security finds CVE-2025-31129 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.