Service interrupt via unbounded user-file parsing
Published Aug 19, 2026 · Updated Aug 19, 2026
Denial of service in Moby BuildKit before 0.31.1 allows attackers to terminate buildkitd via a malicious base image or build. In executor/oci/user.go and solver/llbsolver/ops/user_linux.go, BuildKit resolves named users and groups by reading attacker-controlled /etc/passwd and /etc/group with no size limit, so oversized files can consume memory until the daemon is OOM-killed. Exposure requires attacker influence over the build definition or base image and a path that performs user or group name resolution; the consequence is a build service crash, not code execution or direct data access.
Summary
What happened
Denial of service in Moby BuildKit before 0.31.1 allows attackers to terminate buildkitd via a malicious base image or build. In executor/oci/user.go and solver/llbsolver/ops/user_linux.go, BuildKit resolves named users and groups by reading attacker-controlled /etc/passwd and /etc/group with no size limit, so oversized files can consume memory until the daemon is OOM-killed. Exposure requires attacker influence over the build definition or base image and a path that performs user or group name resolution; the consequence is a build service crash, not code execution or direct data access.
The record
- CVE
- CVE-2026-61712
- Published
- Aug 19, 2026
- Updated
- Aug 19, 2026
- Vendor
- Moby Project
- Product
- BuildKit
- Classifications
- CWE-770, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 19, 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=< 0.31.1
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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