---
id: CVE-2026-106439
title: Hydra is a framework for elegantly configuring complex applications
summary: >-
  Hydra is a framework for elegantly configuring complex applications. From
  1.3.4 until 1.3.7 and 1.4.0.dev10, Hydra stores legacy instantiate target
  blocklists and related execution-policy collections in mutable module-level
  state. An att…
severity: high
cvss: 8.5
cvssVector: 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'
cwe:
  - CWE-470
  - CWE-693
vendor: hydra-ecosystem
product: hydra
affected:
  - 'hydra >= 1.3.4, < 1.3.7'
  - 'hydra >= 1.4.0.dev4, < 1.4.0.dev10'
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T20:17:25.917'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106439'
references:
  - url: >-
      https://github.com/hydra-ecosystem/hydra/commit/0dd18084589a3d3e577d1f1a8a48fb485c94a5e6
    label: security-advisories@github.com
  - url: >-
      https://github.com/hydra-ecosystem/hydra/commit/4720dfca2bde27fa140ec287a05709668fbdf168
    label: security-advisories@github.com
  - url: 'https://github.com/hydra-ecosystem/hydra/releases/tag/v1.3.7'
    label: security-advisories@github.com
  - url: >-
      https://github.com/hydra-ecosystem/hydra/security/advisories/GHSA-mwj6-rfh8-7qf4
    label: security-advisories@github.com
  - url: >-
      https://github.com/hydra-ecosystem/hydra/security/advisories/GHSA-mwj6-rfh8-7qf4
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-06T19:48:26.207340Z'
cvssSource: cna
ingestedAt: '2026-10-06T19:13:33.855Z'
---

## Overview

Hydra is a framework for elegantly configuring complex applications. From 1.3.4 until 1.3.7 and 1.4.0.dev10, Hydra stores legacy instantiate target blocklists and related execution-policy collections in mutable module-level state. An attacker who controls multiple sibling target entries can resolve hydra._internal.target_policy.UNCONTROLLED_EXECUTION_TARGETS.discard through instantiate(), remove a denied target, and then invoke that target because sibling nodes are processed in insertion order against the same modified policy. The mutation persists in process-global state and can enable code execution with the application's privileges, while a narrow execution whitelist supplied by trusted Python code is not bypassed by the reported direct mutation path. This issue is fixed in versions 1.3.7 and 1.4.0.dev10.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.