CVE-2026-106442: CWE-184: Incomplete List of Disallowed Inputs in hydra-ecosystem hydra

Hydra versions >=1.3.4 <1.3.6 and >=1.4.0.dev0 <1.4.0.dev9 have an incomplete check in the instantiate() target blacklist introduced for a previous CVE. Execution wrappers like timeit.timeit, pickle.loads deserialization, aliases, callable-returning helpers, generic dispatch, and deferred calls can obscure or defer the effective callable, bypassing the name-based authorization intended to block unsafe targets. This allows code execution with the application's privileges if an attacker can cause the application to instantiate untrusted Hydra configuration. The vulnerability is addressed in versions 1.3.6 and 1.4.0.dev9.

An attacker able to supply untrusted Hydra configuration can exploit this vulnerability to execute arbitrary code with the privileges of the affected application. This can lead to full compromise of the application environment, including confidentiality, integrity, and availability impacts.

Upgrade affected Hydra versions to 1.3.6 or later, or 1.4.0.dev9 or later, where the vulnerability is fixed. No other mitigations are indicated by the vendor advisory.