Vulnerability · Published Jul 21, 2026 · Assigned by Docker
CVE-2026-15791LLB file operation can be tricked to remove /tmp directory contents
Low 3.3
In plain English
A low-severity path traversal in BuildKit from moby. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).
Severity (CVSS 4.0)3.3Low
Exploit odds (30 days)0.2%top 83.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A crafted message in the BuildKit low-level build API can be used to remove the contents of the /tmp directory. The action that can normally be used to delete files inside the build container rootfs can escape into the real host temp directory.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:26.04:LTS | docker.io | no fix listed | UBUNTU-CVE-2026-15791 |
| Ubuntu:26.10 | docker.io | no fix listed | UBUNTU-CVE-2026-15791 |
| Ubuntu:26.04:LTS | docker.io-app | no fix listed | UBUNTU-CVE-2026-15791 |
| Ubuntu:26.10 | docker.io-app | no fix listed | UBUNTU-CVE-2026-15791 |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N