Conda BuildApplication · Anaconda

CVE-2025-32799

CRITICAL · 9.8 CVSS v3.1 Published 2025-06-16
Fix available
A fix is available. Upgrade to 25.4.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Conda-build contains commands and tools to build conda packages. Prior to version 25.4.0, the conda-build processing logic is vulnerable to path traversal (Tarslip) attacks due to improper sanitization of tar entry paths. Attackers can craft tar archives containing entries with directory traversal sequences to write files outside the intended extraction directory. This could lead to arbitrary file overwrites, privilege escalation, or code execution if sensitive locations are targeted. This issue has been patched in version 25.4.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Conda-build versions prior to 25.4.0 contain a path traversal (Tarslip) vulnerability in the tar archive processing logic. The software fails to properly sanitize tar entry paths, allowing attackers to craft malicious tar archives containing directory traversal sequences (e.g., ../../) that write files outside the intended extraction directory.

MitigationUpgrade conda-build to version 25.4.0 or later which contains the patch for proper tar entry path sanitization. If immediate patching is not feasible, implement input validation to reject tar entries containing traversal sequences before extraction.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Conda BuildApplication
Affected:< 25.4.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify conda-build is installed
    Run 'conda list conda-build' or 'pip show conda-build' to check if the package is present in your environment
    Affected if conda-build is not installed, the vulnerability does not apply
  2. Determine the installed version of conda-build
    Run 'conda list conda-build' or 'conda-build --version' to retrieve the exact version number
    Affected if The version displayed is less than 25.4.0 (for example, 25.3.0, 25.2.0, etc.)
  3. Confirm the vulnerability applies to tar extraction workflows
    Verify that conda-build is used to build packages from recipes, which involves extracting tar archives containing build dependencies or source tarballs
    Affected if You use conda-build to extract or build from tar archives - this is the core function where the path traversal flaw can be triggered

You are affected if conda-build is installed and its version is below 25.4.0, and you use it to process tar archives during package building.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 25.4.0 or later
Fixed in 25.4.0
Vendor patch github.com →
Interim mitigation

Upgrade conda-build to version 25.4.0 or later which contains the patch for proper tar entry path sanitization. If immediate patching is not feasible, implement input validation to reject tar entries containing traversal sequences before extraction.

Recommended fix High confidence

25.4.0

  1. Upgrade conda-build to version 25.4.0 or later using: conda install -c conda-forge conda-build>=25.4.0
  2. Alternatively, upgrade via pip: pip install --upgrade conda-build>=25.4.0
  3. Verify the upgrade was successful by running: conda-build --version
Caveat Review conda-build 25.4.0 release notes for any changes that may affect existing build workflows

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Conda Build Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-32799 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data