High severity · published Jul 21, 2026
CVE-2026-15789
Malicious client can bypass destination directory validation on local sources upload
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
A custom client can produce such an upload request to the BuildKit daemon that files can escape from the BuildKit-controlled state directory. The client needs to have valid permissions to access the BuildKit control API to issue builds, e.g., bypass authentication, etc.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BU
BuildKit · moby
before 0.31.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-15789
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-15789
Vendor Advisory
https://github.com/moby/buildkit/security/advisories/GHSA-g2h8-426c-7976
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