conda py-rattler/rattler_cache Cache Materialization path traversal

Summaryinfo

A vulnerability categorized as critical has been discovered in conda py-rattler and rattler_cache. The impacted element is an unknown function of the component Cache Materialization. The manipulation results in path traversal. This vulnerability is reported as CVE-2026-53956. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in conda py-rattler and rattler_cache (affected version unknown). It has been classified as critical. Affected is an unknown functionality of the component Cache Materialization. The manipulation with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Rattler is a library that provides common functionality used within the conda ecosystem. `rattler_cache` prior to version 0.9.0 and `py-rattler` prior to version 0.24.0 were vulnerable to package-cache path traversal when handling package metadata from conda channels. During cache materialization, the `ratter_cache` code used the package record `build` string as part of a cache key that was joined into a filesystem path. A malicious or untrusted channel could publish repodata with path separators or traversal components in that field, causing package contents to be written outside the configured package cache directory. The issue requires use of a malicious or otherwise untrusted conda channel. Curated channels that validate package metadata are not expected to allow malformed build strings of this form. Users should upgrade to `rattler_cache` version 0.9.0 or `py-rattler` version 0.24.0 and avoid untrusted conda channels.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-53956 since 06/11/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/09/2026). The MITRE ATT&CK project declares the attack technique as T1006.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• conda

Name

• py-rattler
• rattler_cache

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