CVE-2025-61677 is a low-severity (CVSS 2.5) Deserialization of Untrusted Data vulnerability in datachain. A fix is available for datachain — see the affected versions and patch details below.
DataChain: Deserialization of Untrusted Data from Environment Variables
Exploitation Status
No confirmed exploitation observed yet
- 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-2025-61677.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
datachainReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
DataChain is a Python-based AI-data warehouse for transforming and analyzing unstructured data. Versions 0.34.1 and below allow for deseriaization of untrusted data because of the way the DataChain library reads serialized objects from environment variables (such as DATACHAIN__METASTORE and DATACHAIN__WAREHOUSE) in the loader.py module. An attacker with the ability to set these environment variables can trigger code execution when the application loads. This issue is fixed in version 0.34.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | datachain | all versions | 0.34.2pip install --upgrade 'datachain==0.34.2' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for datachain, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update datachain to 0.34.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61677 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.
Frequently Asked Questions
Is CVE-2025-61677 in your dependencies?
Find it across PyPI, including transitive dependencies.