CVE-2026-25632
EPyT-Flow vulnerable to unsafe JSON deserialization (__type__)
Description
### Impact EPyT-Flow’s REST API parses attacker-controlled JSON request bodies using a custom deserializer (my_load_from_json) that supports a __type__ field. When __type__ is present, the deserializer dynamically imports an attacker-specified module/class and instantiates it with attacker-supplied arguments. This allows invoking dangerous classes such as subprocess.Popen, which can lead to OS command execution during JSON parsing. This also affects the loading of JSON files. ### Patches EPyT-Flow has been patched in 0.16.1 -- affects all versions <= 0.16.0 ### Workarounds Do not load any JSON from untrusted sources and do not expose the REST API. ### Credits EPyT-Flow thanks Jarrett Chan (@syphonetic) for detecting and reporting the bug.
How to fix CVE-2026-25632
To remediate CVE-2026-25632, upgrade the affected package to a fixed version below.
- —upgrade to 0.16.1 or later
Is CVE-2026-25632 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 0.16.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |