Bug 2546940 (CVE-2026-106439)

Summary: CVE-2026-106439 hydra-core: hydra-core: Arbitrary code execution via mutable execution policy manipulation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: alinfoot, bbrownin, dtrifiro, weaton
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in hydra-core. Target execution policies used during object instantiation are stored in mutable module-level state. An attacker who supplies crafted configuration entries can manipulate this policy to remove restrictions on blocked targets. Successful exploitation allows the attacker to execute arbitrary code with the permissions of the running application.
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Description OSIDB Bzimport 2026-10-06 19:17:23 UTC 
Hydra is a framework for elegantly configuring complex applications. From 1.3.4 until 1.3.7 and 1.4.0.dev10, Hydra stores legacy instantiate target blocklists and related execution-policy collections in mutable module-level state. An attacker who controls multiple sibling target entries can resolve hydra._internal.target_policy.UNCONTROLLED_EXECUTION_TARGETS.discard through instantiate(), remove a denied target, and then invoke that target because sibling nodes are processed in insertion order against the same modified policy. The mutation persists in process-global state and can enable code execution with the application's privileges, while a narrow execution whitelist supplied by trusted Python code is not bypassed by the reported direct mutation path. This issue is fixed in versions 1.3.7 and 1.4.0.dev10.