CVE-2025-70974 — fastjson
CRITICALCVE-2025-70974 is a critical-severity (CVSS 10) CWE-829 vulnerability in com.alibaba:fastjson. A fix is available for com.alibaba:fastjson — see the affected versions and patch details below.
FASTJSON Includes Functionality from Untrusted Control Sphere
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-70974.
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-2025-70974 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% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
com.alibaba: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
Fastjson before 1.2.48 mishandles autoType because, when an @type key is in a JSON document, and the value of that key is the name of a Java class, there may be calls to certain public methods of that class. Depending on the behavior of those methods, there may be JNDI injection with an attacker-supplied payload located elsewhere in that JSON document. This was exploited in the wild in 2023 through 2025. NOTE: this issue exists because of an incomplete fix for CVE-2017-18349. Also, a later bypass is covered by CVE-2022-25845.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.alibaba:fastjson | all versions | 1.2.48com.alibaba:fastjson:1.2.48 |
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 1.2.48 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-70974 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-2025-70974 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-70974. 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-2025-70974 in your dependencies?
O3 Security finds CVE-2025-70974 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.