CVE-2025-32784: conda-forge-webservices has an Unauthorized Artifact Modification Race Condition

Severity: high (CVSS 7.5 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-04-15 · updated 2026-06-17
Weakness: CWE-367

Description

conda-forge-webservices is the web app deployed to run conda-forge admin commands and linting. In versions prior to 2025.4.10, a race condition vulnerability has been identified in the conda-forge-webservices component used within the shared build infrastructure. This vulnerability, categorized as a Time-of-Check to Time-of-Use (TOCTOU) issue, can be exploited to introduce unauthorized modifications to build artifacts stored in the cf-staging Anaconda channel. Exploitation may result in the unauthorized publication of malicious artifacts to the production conda-forge channel. The core vulnerability results from the absence of atomicity between the hash validation and the artifact copy operation. This gap allows an attacker, with access to the cf-staging token, to overwrite the validated artifact with a malicious version immediately after hash verification, but before the copy action is executed. As the cf-staging channel permits artifact overwrites, such an operation can be carried out using the anaconda upload --force command. This vulnerability is fixed in 2025.4.10.

Affected products

conda-forge-webservices: before 2025.4.10

References

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