GHSA-C3WX-C55W-PXJQ

Vulnerability from github – Published: 2026-10-07 18:03 – Updated: 2026-10-07 18:03
VLAI
Summary
Hydra logging configuration permits unsafe callable resolution
Details

Summary

Hydra passed its Python logging configuration to logging.config.dictConfig(). Python's logging configurator can resolve and invoke importable classes and factories named by configuration, including handler class values and formatter, filter, handler, queue, and listener () factories.

This logging path was not mediated by Hydra's target policy. In versions that already protected instantiate(), logging resolution bypassed those controls because it did not use instantiate().

An attacker who can control a Hydra logging configuration can use a custom class or factory to execute code with the application's privileges when Hydra configures logging.

Fix

Hydra now applies its target policy to callable resolution and invocation in Hydra-configured Python logging. It authorizes custom factories, handlers, formatters, filters, queues, listeners, aliases, discovery results, and callable results before they can be used.

Hydra 1.3.6 uses the hardened blacklist. The Hydra 1.3 blacklist is a best-effort, defense-in-depth measure. It is not a complete security boundary and does not make untrusted logging configuration safe.

Hydra 1.4.0.dev9 introduces the execution whitelist as the recommended primary boundary, with the blacklist retained as a deprecated compatibility fallback. When an execution whitelist is supplied, Hydra automatically permits targets used by its built-in logging configurations, while custom logging integrations must be explicitly authorized by trusted Python code. If no whitelist is supplied, Hydra warns and preserves legacy fallback behavior.

Remediation

Upgrade to Hydra 1.3.6, or to Hydra 1.4.0.dev9 or later when testing the 1.4 prerelease line.

On Hydra 1.3, do not compose logging configuration from untrusted sources. On Hydra 1.4 and later, constrain custom logging targets with a narrow execution whitelist supplied by trusted Python code. The execution whitelist controls callable selection; it is not general validation of all logging settings.

For Hydra 1.4 execution-whitelist configuration, see:

https://hydra.cc/docs/advanced/execution_whitelist/

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "hydra-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.3.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "hydra-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.4.0.dev0"
            },
            {
              "fixed": "1.4.0.dev9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-106441"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-07T18:03:55Z",
    "nvd_published_at": "2026-10-06T19:18:13Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nHydra passed its Python logging configuration to `logging.config.dictConfig()`. Python\u0027s logging configurator can resolve and invoke importable classes and factories named by configuration, including handler `class` values and formatter, filter, handler, queue, and listener `()` factories.\n\nThis logging path was not mediated by Hydra\u0027s target policy. In versions that already protected `instantiate()`, logging resolution bypassed those controls because it did not use `instantiate()`.\n\nAn attacker who can control a Hydra logging configuration can use a custom class or factory to execute code with the application\u0027s privileges when Hydra configures logging.\n\n## Fix\n\nHydra now applies its target policy to callable resolution and invocation in Hydra-configured Python logging. It authorizes custom factories, handlers, formatters, filters, queues, listeners, aliases, discovery results, and callable results before they can be used.\n\nHydra 1.3.6 uses the hardened blacklist. The Hydra 1.3 blacklist is a best-effort, defense-in-depth measure. It is not a complete security boundary and does not make untrusted logging configuration safe.\n\nHydra 1.4.0.dev9 introduces the execution whitelist as the recommended primary boundary, with the blacklist retained as a deprecated compatibility fallback. When an execution whitelist is supplied, Hydra automatically permits targets used by its built-in logging configurations, while custom logging integrations must be explicitly authorized by trusted Python code. If no whitelist is supplied, Hydra warns and preserves legacy fallback behavior.\n\n## Remediation\n\nUpgrade to Hydra 1.3.6, or to Hydra 1.4.0.dev9 or later when testing the 1.4 prerelease line.\n\nOn Hydra 1.3, do not compose logging configuration from untrusted sources. On Hydra 1.4 and later, constrain custom logging targets with a narrow execution whitelist supplied by trusted Python code. The execution whitelist controls callable selection; it is not general validation of all logging settings.\n\nFor Hydra 1.4 execution-whitelist configuration, see:\n\nhttps://hydra.cc/docs/advanced/execution_whitelist/",
  "id": "GHSA-c3wx-c55w-pxjq",
  "modified": "2026-10-07T18:03:55Z",
  "published": "2026-10-07T18:03:55Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/hydra-ecosystem/hydra/security/advisories/GHSA-c3wx-c55w-pxjq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106441"
    },
    {
      "type": "WEB",
      "url": "https://github.com/hydra-ecosystem/hydra/pull/3420"
    },
    {
      "type": "WEB",
      "url": "https://github.com/hydra-ecosystem/hydra/commit/76bfc30ce1f3105416941dd2e3a562568e369120"
    },
    {
      "type": "WEB",
      "url": "https://github.com/hydra-ecosystem/hydra/commit/ff3e4dba890c29a21d8c2bb867ee87d37ccf21d0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/hydra-ecosystem/hydra"
    },
    {
      "type": "WEB",
      "url": "https://github.com/hydra-ecosystem/hydra/releases/tag/v1.3.6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Hydra logging configuration permits unsafe callable resolution"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.