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Rattler vulnerable to package cache path traversal via conda package build string

Moderate severity GitHub Reviewed Published Jun 2, 2026 in conda/rattler • Updated Jul 9, 2026

Package

pip py_rattler (pip)

Affected versions

<= 0.23.2

Patched versions

0.24.0
cargo rattler_cache (Rust)
<= 0.8.2
0.9.0

Description

rattler_cache and py-rattler 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 a patched version and avoid untrusted conda channels.

References

@baszalmstra baszalmstra published to conda/rattler Jun 2, 2026
Published to the GitHub Advisory Database Jul 9, 2026
Reviewed Jul 9, 2026
Last updated Jul 9, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(10th percentile)

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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. Learn more on MITRE.

External Control of File Name or Path

The product allows user input to control or influence paths or file names that are used in filesystem operations. Learn more on MITRE.

CVE ID

CVE-2026-53956

GHSA ID

GHSA-h672-p7h7-97v9

Source code

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