GHSA-xjrr-xv9m-4pw5 is a critical-severity (CVSS 9.8) Improper Input Validation vulnerability in com.alibaba:fastjson. 2 public exploit references exist, so weaponization risk is real. A fix is available for com.alibaba:fastjson — see the affected versions and patch details below.
Improper Input Validation in alilibaba:fastjson
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
GHSA-xjrr-xv9m-4pw5 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 377,166 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
com.alibaba:fastjson☕ro.pippo:pippo-fastjsonReal-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
parseObject in Fastjson before 1.2.25, as used in FastjsonEngine in Pippo 1.11.0 and other products, allows remote attackers to execute arbitrary code via a crafted JSON request, as demonstrated by a crafted rmi:// URI in the dataSourceName field of HTTP POST data to the Pippo /json URI, which is mishandled in AjaxApplication.java.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.alibaba:fastjson | all versions | 1.2.31com.alibaba:fastjson:1.2.31 |
| ☕Maven | ro.pippo:pippo-fastjson | all versions | 1.12.0ro.pippo:pippo-fastjson:1.12.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.alibaba:fastjson, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.alibaba:fastjson to 1.2.31 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xjrr-xv9m-4pw5 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 GHSA-xjrr-xv9m-4pw5 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-xjrr-xv9m-4pw5. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect GHSA-xjrr-xv9m-4pw5
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-xjrr-xv9m-4pw5 -u https://target- Template
- Fastjson Insecure Deserialization - Remote Code Execution
- Severity
- critical
- Impact
- Successful exploitation allows complete system compromise through remote code execution, enabling attackers to execute arbitrary commands, access sensitive data, and establish persistent backdoors on the target system.
- Remediation
- Update Fastjson to version 1.2.25 or later which includes security patches for this vulnerability.Disable autotype functionality by setting `fastjson.parser.autoTypeSupport=false`.Implement strict whitelist filtering for `@type` annotations, validate and sanitize all JSON input.Use Web Application Firewalls (WAF) to filter malicious requests, and regularly audit dependencies for known vulnerabilities. Consider migrating to safer JSON parsing libraries like Jackson with secure configurations.
Template by ProjectDiscovery nuclei-templates (night), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is GHSA-xjrr-xv9m-4pw5 in your dependencies?
O3 Security finds GHSA-xjrr-xv9m-4pw5 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.