CVE-2025-32800: Conda-build vulnerable to supply chain attack vector due to pyproject.toml referring to dependencies not present in PyPI

Vulnerability summary

CVE-2025-32800 is a critical (CVSS 9.8) vulnerability in anaconda conda-build. EPSS estimates a 0.65% chance of exploitation in the next 30 days, higher than 50.3% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 16-06-2025
   PublishedVulnerability first disclosed.
2. 17-06-2025
   Last modifiedVulnerability information updated.

Description

Conda-build contains commands and tools to build conda packages. Prior to version 25.3.0, the pyproject.toml lists conda-index as a Python dependency. This package is not published in PyPI. An attacker could claim this namespace and upload arbitrary (malicious) code to the package, and then exploit pip install commands by injecting the malicious dependency in the solve. This issue has been fixed in version 25.3.0. A workaround involves using --no-deps for pip install-ing the project from the repository.

• CWE-1357Reliance on Insufficiently Trustworthy ComponentThe product is built from multiple separate components, but it uses a component that is not sufficiently trusted to meet expectations for security, reliability, updateability, and maintainability.