vulnerability / NVI-00011805 / Revision 3
Hydra: Optuna custom_search_space can resolve and execute untrusted callables via get_method
GitHub lists this reviewed advisory for hydra-optuna-sweeper, hydra-optuna-sweeper. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.8 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
7.8 HIGH (3.1)
security-advisories@github.com severity; no combined Null risk score.
0.271%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.19334. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
hydra-optuna-sweeper
source listed>= 1.2.0, < 1.3.0
## Summary `hydra-optuna-sweeper` accepted a configuration-controlled dotted path in `hydra.sweeper.custom_search_space`, resolved it with the lower-level `hydra.utils.get_method()` API, and later invoked the returned callable. Hydra's object-lookup helpers intentionally trust their input and do not apply the execution policy used by `instantiate()` and logging configuration. As a result, untrusted Optuna multirun configuration could select installed Python code for execution in the Hydra controller process. ## Impact Exploitation requires control of an application's Optuna sweep configuration or command-line overrides and an importable callable in the application's environment. Selected code runs with the privileges of the application. On affected Hydra 1.4 development releases, this path bypasses an execution whitelist provided by trusted application code. Hydra 1.3 has no execution-whitelist security boundary; there, the same change restores the legacy blocklist as defense in depth. ## Fix The Optuna sweeper now resolves the configured callback through `hydra.utils.instantiate()` as a partial callable. On Hydra 1.4, the active execution whitelist therefore authorizes the
hydra-optuna-sweeper
source listed>= 1.4.0.dev4, < 1.4.0.dev10
## Summary `hydra-optuna-sweeper` accepted a configuration-controlled dotted path in `hydra.sweeper.custom_search_space`, resolved it with the lower-level `hydra.utils.get_method()` API, and later invoked the returned callable. Hydra's object-lookup helpers intentionally trust their input and do not apply the execution policy used by `instantiate()` and logging configuration. As a result, untrusted Optuna multirun configuration could select installed Python code for execution in the Hydra controller process. ## Impact Exploitation requires control of an application's Optuna sweep configuration or command-line overrides and an importable callable in the application's environment. Selected code runs with the privileges of the application. On affected Hydra 1.4 development releases, this path bypasses an execution whitelist provided by trusted application code. Hydra 1.3 has no execution-whitelist security boundary; there, the same change restores the legacy blocklist as defense in depth. ## Fix The Optuna sweeper now resolves the configured callback through `hydra.utils.instantiate()` as a partial callable. On Hydra 1.4, the active execution whitelist therefore authorizes the
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-5jjj-9xc3-rm56 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-106440 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2026-106440 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.