Vulnerability · Published Jul 20, 2026 · Assigned by Docker
CVE-2026-15788WCOW cache mount source selector resolves NTFS junctions outside of cache root
Medium 5.6
In plain English
A medium-severity security flaw 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 0.4% (higher than 36% of all known vulnerabilities).
Severity (CVSS 4.0)5.6Medium
Exploit odds (30 days)0.4%top 64.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
BuildKit's cache mount source= selector on Windows Container on Windows (WCOW) workers does not detect NTFS directory junctions placed inside the cache root. A build authored by an untrusted user on a WCOW-configured BuildKit daemon can read arbitrary host files reachable to the BuildKit daemon process.
Affected products (as reported)
Weakness: CWE-59 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N