CVE-2026-25632: Epyt flow EPyT-Flow Vulnerable To Unsafe JSON Vulnerability

CRITICAL
Advisory Identifier: GHSA-74vm-8frp-7w68
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CVSS 10.0
CWE-502
Published
Advisory Summary

CVE-2026-25632 is a CRITICAL (CVSS 10.0) epyt-flow vulnerable to unsafe json vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Epyt flow libraries in the PyPI ecosystem. The issue involves epyt-flow vulnerable to unsafe json deserialization (__type__). Remediation is available by upgrading affected packages to version 0.16.1.

CVE-2026-25632 at a Glance

CVE Identifier CVE-2026-25632
GHSA Identifier GHSA-74vm-8frp-7w68
Severity CRITICAL
CVSS v3.1 Base Score 10.0
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Epyt flow
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 10.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-25632

To remediate this vulnerability, upgrade all affected Epyt flow dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

epyt-flow fixed: 0.16.1 
pip install epyt-flow>=0.16.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show epyt-flow

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-25632, inspect your installed packages using pip:

pip show epyt-flow

Analyze the terminal output to locate any version of Epyt flow in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.16.1), your application is affected.

Note: The pip show epyt-flow command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Epyt flow, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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.

CVE-2026-25632 Affected Epyt flow Versions

1 component(s)
Fixed Versions:
0.16.1
Product / Package Ecosystem Affected Versions Fixed Version
epyt-flow
pypi/epyt-flow
PyPI
< 0.16.1
0.16.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/WaterFutures/EPyT-Flow/security/advisories/GHSA-74vm-8frp-7w68
NVD — CVE-2026-25632 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25632
Security Fix Commit FIX COMMIT
https://github.com/WaterFutures/EPyT-Flow/commit/3fff9151494c7dbc72073830b734f0a7e550e385
Epyt flow Source Repository REPOSITORY
https://github.com/WaterFutures/EPyT-Flow
Epyt flow Release RELEASE
https://github.com/WaterFutures/EPyT-Flow/releases/tag/v0.16.1

Frequently Asked Questions

What is CVE-2026-25632?
CVE-2026-25632 is a security vulnerability in Epyt flow involving EPyT-Flow vulnerable to unsafe JSON deserialization (__type__) under CWE-502: Deserialization of Untrusted Data.
Which Epyt flow versions are affected?
Affected versions include releases prior to 0.16.1 across affected packages: epyt-flow.
What version fixes CVE-2026-25632?
Upgrading to 0.16.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is epyt-flow affected?
Yes, epyt-flow is affected in releases prior to 0.16.1. Upgrade your dependency to 0.16.1 or later.
What is the CVSS score of CVE-2026-25632?
CVE-2026-25632 has a CVSS v3.1 base score of 10.0 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2026-25632?
CVE-2026-25632 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check PyPI dependencies for CVE-2026-25632?
Run the dependency tree command: 'pip show epyt-flow'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-74vm-8frp-7w68",
  "modified" : "2026-02-06T21:43:49Z",
  "published" : "2026-02-04T20:34:28Z",
  "aliases" : [ "CVE-2026-25632" ],
  "summary" : "EPyT-Flow vulnerable to unsafe JSON deserialization (__type__)",
  "details" : "### Impact\nEPyT-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.\n\n### Patches\nEPyT-Flow  has been patched in 0.16.1 -- affects all versions <= 0.16.0\n\n### Workarounds\nDo not load any JSON from untrusted sources and do not expose the REST API.\n\n### Credits\nEPyT-Flow  thanks Jarrett Chan (@syphonetic) for detecting and reporting the bug.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "epyt-flow"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.16.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/WaterFutures/EPyT-Flow/security/advisories/GHSA-74vm-8frp-7w68"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25632"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WaterFutures/EPyT-Flow/commit/3fff9151494c7dbc72073830b734f0a7e550e385"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/WaterFutures/EPyT-Flow"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/WaterFutures/EPyT-Flow/releases/tag/v0.16.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-04T20:34:28Z",
    "nvd_published_at" : "2026-02-06T21:16:18Z"
  }
}