{"id":"CVE-2026-40320","aliases":["GHSA-7xjm-g8f4-rp26","PYSEC-2026-2488"],"url":"https://o3.security/vulnerability/CVE-2026-40320","summary":"Giskard has an Unsandboxed Jinja2 Template Rendering in ConformityCheck","details":"## Summary\n \nThe `ConformityCheck` class in `giskard-checks` rendered the `rule` parameter through Jinja2's default `Template()` constructor. Because the `rule` string is silently interpreted as a Jinja2 template, a developer may not realize that template expressions embedded in rule definitions are evaluated at runtime. In a scenario where check definitions are loaded from an untrusted source (e.g. a shared project file or externally contributed configuration), this could lead to arbitrary code execution.\n\n`giskard-checks` is a local developer testing library with no network-facing service. Check definitions, including the `rule` parameter, are provided in application code or project configuration files and executed locally. Exploitation requires write access to a check definition and subsequent execution of the test suite by a developer.\n\nHowever, the implicit template evaluation of the `rule` parameter is not obvious from the API surface. This hidden behavior increases the likelihood of a developer inadvertently passing untrusted input to it when integrating the library into a larger system. \n\n## Affected Component\n \n`conformity.py`, line 59:\n```python\nfrom jinja2 import Template\n...\nformatted_rule = Template(self.rule).render(trace=trace)\n```\n \n## Affected Versions\n \n`giskard-checks` < 1.0.2b1\n \n## Patched Version\n \n`giskard-checks` >= **1.0.2b1** (template parsing removed from rule evaluation entirely)\n \n## Remediation\n \nUpgrade to `giskard-checks` >= 1.0.2b1. The template rendering has been removed from rule evaluation.\n \n## Credit\n \nGiskard-AI thanks @dhabaleshwar for identifying the unsandboxed template usage.","published":"2026-04-17T17:25:50.449Z","modified":"2026-08-29T11:45:58.134256524Z","cvss":null,"epss":{"score":0.00144,"percentile":0.04158,"asOf":"2026-08-10"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"giskard-checks","fixedVersion":"1.0.2b1"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/Giskard-AI/giskard-oss/releases/tag/giskard-checks%2Fv1.0.2b1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40320.json"},{"type":"ADVISORY","url":"https://github.com/Giskard-AI/giskard-oss/security/advisories/GHSA-7xjm-g8f4-rp26"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40320"},{"type":"PACKAGE","url":"https://github.com/Giskard-AI/giskard-oss"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-29T11:45:58.134256524Z"}}