# CVE-2026-121522: Possible panic from Git source resolver

Status: published. Published: 2026-11-03. Updated: 2026-11-06.

In BuildKit versions v0.26.0 through v0.34.1, a specific build definition that resolves metadata for the same Git source reference twice can cause the BuildKit daemon to panic and crash, interrupting builds handled by that daemon. The issue is fixed in v0.34.2.

## Remediation

- fix: Upgrade BuildKit to v0.34.2 or later. (source: CNA: Docker)
- workaround: Avoid untrusted build definitions. Only specific builds using Git dependencies trigger this issue. (source: CNA: Docker)

## Affected products and versions

- moby / BuildKit (github.com/moby/buildkit): ≥ 0.26.0; < 0.34.2 (affected, semver). Source: CNA: Docker

## Severity and prioritization

- CVSS 4.0: 6.7 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: Docker

- CVSS 4.0: 6.7 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: security@docker.com

- CISA KEV: No listing in collected sources

- EPSS: 0.12% as of 2026-11-06; percentile 1.71%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-476

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/moby/buildkit/security/advisories/GHSA-2fqp-xg6f-v7gj (CNA: Docker; vendor-advisory)

- https://github.com/moby/buildkit/security/advisories/GHSA-2fqp-xg6f-v7gj (security@docker.com)

## Provenance

- CNA: Docker: https://www.cve.org/CVERecord?id=CVE-2026-121522; retrieved 2026-11-06; source updated 2026-11-06

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121522; retrieved 2026-11-07; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-121522; retrieved 2026-11-06; source updated Not reported

Revision: c9deea9f201221e656fe2bedbdde45ff5a17a97425adec6f5f213a2199dbd042

Canonical: https://y2.dev/cve/CVE-2026-121522

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