If a BuildKit daemon with shared or persistent cache first processes such a malicious image, a later build using the victim image may mount the attacker-controlled layer contents as the base image. This can allow code from the malicious image to run in the victim build, for example by replacing a commonly executed path such as /bin/sh. The attacker-controlled code may read build secrets mounted into the build, access other build resources, alter output artifacts, or hang the build.
The issue affects both regular snapshotters and lazy-pulling snapshotters such as stargz.
No advisories yet.
Solution
No solution given by the vendor.
Workaround
Do not share BuildKit daemon cache between trusted and untrusted builds. Use isolated BuildKit daemons or ephemeral builders for untrusted image sources, or prune BuildKit cache after processing untrusted images. Disabling stargz alone is not sufficient because regular snapshotters are also affected.
Mon, 05 Oct 2026 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Moby
Moby buildkit |
|
| Vendors & Products |
Moby
Moby buildkit |
Mon, 05 Oct 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Mon, 05 Oct 2026 18:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A malicious image can advertise DiffIDs from another image while containing different layer contents. In affected versions, BuildKit could use the advertised DiffIDs to derive cache and snapshot identity without validating that they matched the actual layer contents. If a BuildKit daemon with shared or persistent cache first processes such a malicious image, a later build using the victim image may mount the attacker-controlled layer contents as the base image. This can allow code from the malicious image to run in the victim build, for example by replacing a commonly executed path such as /bin/sh. The attacker-controlled code may read build secrets mounted into the build, access other build resources, alter output artifacts, or hang the build. The issue affects both regular snapshotters and lazy-pulling snapshotters such as stargz. | |
| Title | Cache poisoning via unvalidated image layer DiffIDs | |
| Weaknesses | CWE-354 | |
| References |
| |
| Metrics |
cvssV4_0
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Docker
Published:
Updated: 2026-10-05T19:06:41.297Z
Reserved: 2026-09-17T17:17:49.216Z
Link: CVE-2026-93318
Updated: 2026-10-05T19:06:37.814Z
Status : Received
Published: 2026-10-05T18:17:38.080
Modified: 2026-10-05T20:17:28.260
Link: CVE-2026-93318
No data.
OpenCVE Enrichment
Updated: 2026-10-05T21:00:21Z