CVE-2026-53942: Conda Organization Infrastructure: Pwn Request in update workflow allows PR-controlled template rendering with SYNC_TOKEN

Vulnerability summary

CVE-2026-53942 is a critical (CVSS 9.9) Code Injection vulnerability in conda infrastructure.

Timeline

1. 23-10-2026
   PublishedVulnerability first disclosed.
2. 23-10-2026
   Last modifiedVulnerability information updated.

Description

Conda Organization Infrastructure is a centralized location for infrastructure codes. Prior to commit 9c0f238, a GitHub Actions Pwn Request vulnerability appears to remain present in conda/conda. The affected workflow is .github/workflows/update.yml. It is triggered by issue_comment events containing @conda-bot render or @conda-bot recreate. For the render path, the workflow obtains the pull request head repository and branch from the PR API, checks out that PR-controlled repository/ref using secrets.SYNC_TOKEN, and then runs conda/actions/template-files@7f6830b1428a9bd47f0b068892c77eae95207037. The external template-files action reads its default configuration and templates from the checked-out working directory. In the confirmed finding, that action uses an unsandboxed Jinja2 environment to render attacker-controlled template content. This creates a Pwn Request chain in which an untrusted PR/comment path can reach template rendering in a privileged token context. This issue has been patched via commit 9c0f238.

• CWE-94Improper Control of Generation of Code ('Code Injection')The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.