TI-2026-68039 Aliases CVE-2026-93321

Malformed LLB definition crashes the BuildKit daemon

LOW 29CWE-129Published 2026-10-05 · Updated 2026-10-06

Key facts

Attack vector: Local
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Deferred Red Hat: fix deferred

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-129 and the CVSS impact.

Summary

moby BuildKit through 0.33.0 is affected. Improper validation of an array index (CWE-129) lets a malicious frontend submit an LLB definition that makes buildkitd panic and terminate. A local attacker without privileges can interrupt all builds running on that daemon.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

A malicious frontend can submit an LLB definition that causes buildkitd to panic and terminate, interrupting all builds running on that daemon.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00155 4th percentileScored 2026-11-07

Fix Deferred Red Hat: fix deferred

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
moby	BuildKit	up to 0.33.0	—	No fix listed	CNA

BuildKit Vendormoby Affected up to 0.33.0 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:mobyproject:buildkit::::::::	—	—	Mobyproject

cpe:2.3:a:mobyproject:buildkit:*:*:*:*:*:*:*:* Versions — — ·Mobyproject

Remediation

The sources list no fixed version for BuildKit. Red Hat lists Red Hat Quay 3 as affected, with no fix available.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Quay 3	Affected	No fix yet: Fix deferred

Not affected: 1 product

Red Hat Hardened Images

Timeline

2026-10-06 Threatist record created from CVE-2026-93321
2026-10-06 CISA SSVC decision points changed
2026-10-06 Priority changed: MEDIUM → LOW
2026-10-20 Affected versions changed · Red Hat
2026-10-20 CVSS score added · Red Hat
2026-10-21 Affected versions changed · Red Hat

References

Patch 1

https://github.com/moby/buildkit/releases/tag/v0.33.1

Advisory 1

https://github.com/moby/buildkit/security/advisories/GHSA-fjj4-h6vf-m9hj

TI-2026-14229 Tar extraction in moby/go-archive can write outside the destination directory via link following CVSS 4.0HIGH 7.1
TI-2021-12512 Moby HyperKit uninitialized memory use in virtio-sock pci_vtsock_proc_tx CVSS 3.1HIGH 7.1
TI-2024-27462 Moby authz zero length regression CVSS 3.1CRITICAL 10.0
TI-2024-15672 BuildKit interactive containers API does not validate entitlements check CVSS 3.1CRITICAL 9.8
TI-2024-15671 BuildKit possible host system access from mount stub cleaner CVSS 3.1CRITICAL 10.0
TI-2026-26365 Moby: AuthZ plugin bypass with oversized request body CVSS 3.1HIGH 8.8

See all 57 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences