CVE-2022-36085: OPA Compiler: Bypass of WithUnsafeBuiltins using `with` keyword to mock functions

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-09-08 · updated 2026-06-17
Weakness: CWE-20

Description

Open Policy Agent (OPA) is an open source, general-purpose policy engine. The Rego compiler provides a (deprecated) `WithUnsafeBuiltins` function, which allows users to provide a set of built-in functions that should be deemed unsafe — and as such rejected — by the compiler if encountered in the policy compilation stage. A bypass of this protection has been found, where the use of the `with` keyword to mock such a built-in function (a feature introduced in OPA v0.40.0), isn’t taken into account by `WithUnsafeBuiltins`. Multiple conditions need to be met in order to create an adverse effect. Version 0.43.1 contains a patch for this issue. As a workaround, avoid using the `WithUnsafeBuiltins` function and use the `capabilities` feature instead.

Affected products

Openpolicyagent Open Policy Agent: from 0.40.0 before 0.43.1 — fixed in 0.43.1

How to fix

Upgrade to a fixed version: Openpolicyagent Open Policy Agent 0.43.1. Check the vendor advisory for mitigations.

References

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