CVE-2026-93326

Crafted Git build source can bypass certain policy validation

Published Oct 5, 2026 CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed
Description
A build step for a Git source, crafted in a specific way, can bypass some policy validation rules. A malicious build definition can make the repository look like it is coming from a different remote URL than it really is when Git clone is happening. If policy is doing more stricter validation, for example based on commit SHA, commit data, or signatures, then all these validations still apply correctly.

Analysis

AI-generated

Technical impact

The vulnerability arises when a build definition contains a specially crafted Git source step, causing BuildKit to treat the repository as originating from a different URL during the clone process. This enables an attacker to supply code from an unintended source while the system accepts the provided URL as legitimate. The issue only affects validation that relies on the remote URL; checks based on commit SHA, commit data, or signatures remain effective. The weakness is identified as CWE-180.

Affected Systems

Moby BuildKit is the affected product. The specific bug is noted in the release around v0.33.1 and occurs when builds execute optional Build policies that apply Git source rules based solely on the repository URL. Any deployment of BuildKit that utilizes such policies is potentially impacted.

Risk and Exploitability

The CVSS score of 6.0 indicates moderate risk. The EPSS score is not available, and the CVE is not listed in the CISA KEV catalog, so current exploitation likelihood is uncertain. The likely attack vector is an attacker able to inject a malicious build definition into a CI pipeline or a build server that trusts user‑supplied definitions. The flaw requires the specific configuration of URL‑based Git source rules; stricter validations that check commit SHA or signatures remain effective. Exploitation therefore requires both a vulnerable BuildKit installation and authorisation to supply build definitions, making the risk contingent on access controls.

Remediation

Vendor Workaround

Issue only affect special cases when running builds with optional Build policies with specific Git source rules. Only the Git source rules based on the repository URL are affected.


OpenCVE Recommended Actions

  • Upgrade to the latest BuildKit release that contains the fix
  • If an upgrade is not immediately possible, reconfigure your build policy to validate Git sources by commit SHA or signed artifacts and disable rules that rely solely on the repository URL
  • Limit access to build definition creation and validate any repository URLs before allowing a build to proceed

Generated by OpenCVE AI on October 5, 2026 at 21:36 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Moby
Moby buildkit
Vendors & Products Moby
Moby buildkit
Type Values Removed Values Added
Description A build step for a Git source, crafted in a specific way, can bypass some policy validation rules. A malicious build definition can make the repository look like it is coming from a different remote URL than it really is when Git clone is happening. If policy is doing more stricter validation, for example based on commit SHA, commit data, or signatures, then all these validations still apply correctly.
Title Crafted Git build source can bypass certain policy validation
Weaknesses CWE-180
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-180

    Incorrect Behavior Order: Validate Before Canonicalize

Sources

Status
PUBLISHED
Assigner
Docker
Published
Updated
Oct 6, 2026, 1:48 PM
Reserved
Sep 17, 2026, 5:18 PM
Status
Awaiting Analysis
Published
Oct 5, 2026, 9:16 PM
Modified
Oct 6, 2026, 3:08 PM