Arbitrary file write via crafted container ID
Published Mar 27, 2026 · Updated Mar 27, 2026
Path traversal in Moby BuildKit before 0.28.1 allows attackers to write files outside the execution context's state directory. The runc and containerd executor Run paths accepted a frontend-controlled container ID and joined it to the executor root without rejecting slashes or other path characters. Exploitation requires an untrusted custom frontend selected through #syntax or BUILDKIT_SYNTAX; the documented docker/dockerfile frontend is unaffected.
Summary
What happened
Path traversal in Moby BuildKit before 0.28.1 allows attackers to write files outside the execution context's state directory. The runc and containerd executor Run paths accepted a frontend-controlled container ID and joined it to the executor root without rejecting slashes or other path characters. Exploitation requires an untrusted custom frontend selected through #syntax or BUILDKIT_SYNTAX; the documented docker/dockerfile frontend is unaffected.
The record
- CVE
- CVE-2026-33747
- Published
- Mar 27, 2026
- Updated
- Mar 27, 2026
- Vendor
- Moby Project
- Product
- BuildKit
- Classifications
- CWE-22
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 27, 2026CVE publishedPublication date reported by the CVE source.
- Mar 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.28.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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