What’s Vulnerable › Vulnerabilities

CVE-2026-106440: Hydra: Optuna custom_search_space can resolve and execute untrusted callables via get_method

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-06 · updated 2026-10-09
• Weakness: CWE-470

Description

Hydra is a framework for elegantly configuring complex applications. From 1.2.0 until 1.3.0 and 1.4.0.dev10, the hydra-optuna-sweeper package accepts a configuration-controlled dotted path in hydra.sweeper.custom_search_space, resolves it with hydra.utils.get_method(), and later invokes the returned callable in the Hydra controller process. Because get_method() is a trusted-input lookup helper and does not apply the execution policy used by instantiate(), an attacker who controls Optuna sweep configuration or command-line overrides can select importable Python code for execution with the application's privileges, including bypassing a trusted execution whitelist on affected Hydra 1.4 development releases. This issue is fixed in versions 1.3.0 and 1.4.0.dev10.

Affected products

• hydra-ecosystem hydra: from 1.2.0, < 1.3.0; from 1.4.0.dev4, < 1.4.0.dev10

References

• https://github.com/hydra-ecosystem/hydra/commit/0dd18084589a3d3e577d1f1a8a48fb485c94a5e6
• https://github.com/hydra-ecosystem/hydra/commit/4720dfca2bde27fa140ec287a05709668fbdf168
• https://github.com/hydra-ecosystem/hydra/releases/tag/v1.3.7
• https://github.com/hydra-ecosystem/hydra/security/advisories/GHSA-5jjj-9xc3-rm56

Get alerted when CVE-2026-106440 or the next vulnerability affects your stack