Hydra is a framework for elegantly configuring complex applications. From 1.3.4 until 1.3.6 and 1.4.0.dev9, the instantiate() target blacklist introduced for CVE-2026-68508 incompletely checks the effective callable selected by the target field. Execution wrappers such as timeit.timeit, executable deserialization through pickle.loads, aliases, callable-returning helpers, generic dispatch, and deferred calls can obscure or defer the effective target and bypass name-based authorization. An attacker who causes an application to instantiate untrusted Hydra configuration can use these gaps to execute code with the applications privileges. This issue is fixed in versions 1.3.6 and 1.4.0.dev9.
Weakness
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.
Potential Mitigations
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/120.html
- https://cwe.mitre.org/data/definitions/15.html
- https://cwe.mitre.org/data/definitions/182.html
- https://cwe.mitre.org/data/definitions/3.html
- https://cwe.mitre.org/data/definitions/43.html
- https://cwe.mitre.org/data/definitions/6.html
- https://cwe.mitre.org/data/definitions/71.html
- https://cwe.mitre.org/data/definitions/73.html
- https://cwe.mitre.org/data/definitions/85.html
References
- https://github.com/hydra-ecosystem/hydra/commit/2c82bbb3f39603b336cb852461739fdf7a38798a
- https://github.com/hydra-ecosystem/hydra/commit/f462811117b5ecfd2ed652ed52d6b4e3771bd943
- https://github.com/hydra-ecosystem/hydra/pull/3412
- https://github.com/hydra-ecosystem/hydra/pull/3413
- https://github.com/hydra-ecosystem/hydra/releases/tag/v1.3.6
- https://github.com/hydra-ecosystem/hydra/security/advisories/GHSA-rqx7-p7vv-w7hr