CVE-2025-54368: Uv Uv Allows ZIP Payload Obfuscation Vulnerability

MODERATE
Advisory Identifier: GHSA-8qf3-x8v5-2pj8
CWE-436 CWE-20
Published
Advisory Summary

CVE-2025-54368 is a MODERATE uv allows zip payload obfuscation vulnerability (CWE-436: Interpretation Conflict) affecting Uv libraries in the PyPI ecosystem. The issue involves uv allows zip payload obfuscation through parsing differentials. Remediation is available by upgrading affected packages to version 0.8.6.

CVE-2025-54368 at a Glance

CVE Identifier CVE-2025-54368
GHSA Identifier GHSA-8qf3-x8v5-2pj8
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-436: Interpretation Conflict
Affected Product Uv
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2025-54368

To remediate this vulnerability, upgrade all affected Uv dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

uv fixed: 0.8.6
pip install uv>=0.8.6
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show uv

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-54368, inspect your installed packages using pip:

pip show uv

Analyze the terminal output to locate any version of Uv in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.8.6), your application is affected.

Note: The pip show uv command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-436: Interpretation Conflict, where product a handles inputs or steps differently than product b, which causes a to perform incorrect actions based on its perception of b's state. In Uv, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Impact In versions 0.8.5 and earlier of uv, remote ZIP archives were handled in a streamwise fashion, and file entries were not reconciled against the archive's central directory. This enabled two parser differentials against other Python package installers: 1. An attacker could contrive a ZIP archive that would extract with legitimate contents on some package installers, and malicious contents on others due to multiple local file entries. The attacker could choose which installer to target. 2. An attacker could contrive a "stacked" ZIP input with multiple internal ZIPs, which would be handled differently by different package installers. The attacker could choose which installer to target. In both cases, the outcome is that an attacker can produce a ZIP with a consistent digest that expands differently with different installers. The [ZIP standard](https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT) is ambiguous with respect to these behavior differentials. Consequently, these same differentials may be accepted ZIP parsers other than those used in uv. This advisory is for uv in particular, but all consumers of ZIP-based Python package distributions, e.g., pip, are potentially susceptible to similar parser differentials in other ZIP parsers. The practical impact of these differentials is limited by a number of factors: - To be compromised via this vulnerability, user interaction of some sort is required. In particular, the user must run `uv install $package` with an attacker-controlled `$package`. - When using wheel distributions, installation of the malicious package is not sufficient for execution of malicious code, the vicim would need to perform a separate invocation, e.g., `python -c "import $package"`. - If a ZIP-based source distribution (which are less common than tarball source distributions), is encountered, malicious code can be executed during package resolution or installation. uv may invoke the malicious code when building the source distribution into a wheel. - The practical impact of these differentials is limited by a coordinated fix to [Warehouse](https://github.com/pypi/warehouse), PyPI's backend: Warehouse now rejects ZIPs exhibiting these differentials, limiting the ability of an attacker to distribute malicious ZIP distributions via PyPI. As part of that coordinated fix, a review of Warehouse revealed no evidence of exploitation. ## Patches Versions 0.8.6 and newer of uv address both of the parser differentials above, by refusing to process ZIPs with duplicated local file entries or stacked contents. ## Workarounds Users are advised to upgrade to 0.8.6 or newer to address this advisory. Most users should experience no breaking changes as a result of the patch above. However, users who do experience breakage should carefully review their distributions for signs of malicious intent. Users may choose to set `UV_INSECURE_NO_ZIP_VALIDATION=1` to revert to the previous behavior. ## Attribution This vulnerability was discovered separately by two different individuals: Caleb Brown (Google) and Tim Hatch (Netflix).

CVE-2025-54368 Affected Uv Versions

1 component(s)
Fixed Versions:
0.8.6
Product / Package Ecosystem Affected Versions Fixed Version
uv
PyPI
< 0.8.6
0.8.6

References

Frequently Asked Questions

What is CVE-2025-54368?
CVE-2025-54368 is a security vulnerability in Uv involving uv allows ZIP payload obfuscation through parsing differentials under CWE-436: Interpretation Conflict.
Which Uv versions are affected?
Affected versions include releases prior to 0.8.6 across affected packages: uv.
What version fixes CVE-2025-54368?
Upgrading to 0.8.6 (or the latest patched release for your respective branch) resolves the vulnerability.
Is uv affected?
Yes, uv is affected in releases prior to 0.8.6. Upgrade your dependency to 0.8.6 or later.
What CWE is associated with CVE-2025-54368?
CVE-2025-54368 is classified under CWE-436: Interpretation Conflict (Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.).
How can I check PyPI dependencies for CVE-2025-54368?
Run the dependency tree command: 'pip show uv'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8qf3-x8v5-2pj8",
  "modified" : "2025-08-08T14:54:11Z",
  "published" : "2025-08-07T20:52:44Z",
  "aliases" : [ "CVE-2025-54368" ],
  "summary" : "uv allows ZIP payload obfuscation through parsing differentials",
  "details" : "## Impact\n\nIn versions 0.8.5 and earlier of uv, remote ZIP archives were handled in a streamwise fashion, and file entries were not reconciled against the archive's central directory. This enabled two parser differentials against other Python package installers:\n\n1. An attacker could contrive a ZIP archive that would extract with legitimate contents on some package installers, and malicious contents on others due to multiple local file entries. The attacker could choose which installer to target.\n2. An attacker could contrive a \"stacked\" ZIP input with multiple internal ZIPs, which would be handled differently by different package installers. The attacker could choose which installer to target.\n\nIn both cases, the outcome is that an attacker can produce a ZIP with a consistent digest that expands differently with different installers.\n\nThe [ZIP standard](https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT) is ambiguous with respect to these behavior differentials. Consequently, these same differentials may be accepted ZIP parsers other than those used in uv. This advisory is for uv in particular, but all consumers of ZIP-based Python package distributions, e.g., pip, are potentially susceptible to similar parser differentials in other ZIP parsers.\n\nThe practical impact of these differentials is limited by a number of factors:\n\n- To be compromised via this vulnerability, user interaction of some sort is required. In particular, the user must run `uv install $package` with an attacker-controlled `$package`.\n- When using wheel distributions, installation of the malicious package is not sufficient for execution of malicious code, the vicim would need to perform a separate invocation, e.g., `python -c \"import $package\"`.\n- If a ZIP-based source distribution (which are less common than tarball source distributions), is encountered, malicious code can be executed during package resolution or installation. uv may invoke the malicious code when building the source distribution into a wheel.\n- The practical impact of these differentials is limited by a coordinated fix to [Warehouse](https://github.com/pypi/warehouse), PyPI's backend: Warehouse now rejects ZIPs exhibiting these differentials, limiting the ability of an attacker to distribute malicious ZIP distributions via PyPI. As part of that coordinated fix, a review of Warehouse revealed no evidence of exploitation.\n\n## Patches\n\nVersions 0.8.6 and newer of uv address both of the parser differentials above, by refusing to process ZIPs with duplicated local file entries or stacked contents.\n\n## Workarounds\n\nUsers are advised to upgrade to 0.8.6 or newer to address this advisory.\n\nMost users should experience no breaking changes as a result of the patch above. However, users who do experience breakage should carefully review their distributions for signs of malicious intent. Users may choose to set `UV_INSECURE_NO_ZIP_VALIDATION=1` to revert to the previous behavior.\n\n## Attribution\n\nThis vulnerability was discovered separately by two different individuals: Caleb Brown (Google) and Tim Hatch (Netflix).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "uv"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.8.6"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.8.5"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/astral-sh/uv/security/advisories/GHSA-8qf3-x8v5-2pj8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-54368"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/astral-sh/uv/commit/7f1eaf48c193e045ca2c62c4581048765c55505f"
  }, {
    "type" : "WEB",
    "url" : "https://astral.sh/blog/uv-security-advisory-cve-2025-54368"
  }, {
    "type" : "WEB",
    "url" : "https://blog.pypi.org/posts/2025-08-07-wheel-archive-confusion-attacks"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/astral-sh/uv"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-436" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-07T20:52:44Z",
    "nvd_published_at" : "2025-08-08T00:15:26Z"
  }
}