CVE-2026-15788
WCOW cache mount source selector resolves NTFS junctions outside of cache root
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Active
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
WCOW cache mount source selector resolves NTFS junctions outside of cache root
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.
- Record
CVE-2026-15788- CVSS 4.0
- 5.6 Medium
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 - Weakness
- CWE-59
- Updated
- 2026-11-02
EUVDEUVD-2026-46074
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.
- Record
EUVD-2026-46074- CVSS 4.0
- 5.6 Medium
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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-15788- CVSS 4.0
- 5.6 Medium
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/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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-59
- Updated
- 2026-11-02
OSVBELL-CVE-2026-15788
CVE-2026-15788 does not affect BellSoft software
- Record
BELL-CVE-2026-15788- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSV
WCOW cache mount source selector resolves NTFS junctions outside of cache root
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.
- Record
CVE-2026-15788- CVSS 4.0
- 5.6 Medium
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 - Weakness
- CWE-59
- Updated
- 2026-11-02
OSVRHSA-2026:43122
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- Record
RHSA-2026:43122- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVRHSA-2026:44152
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- Record
RHSA-2026:44152- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVRHSA-2026:46988
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- Record
RHSA-2026:46988- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVRHSA-2026:51065
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- Record
RHSA-2026:51065- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
buildahRed Hat:hummingbird:1 From an advisory covering 2 CVEs |
before 0:1.44.0-3.2.hum1 | 0:1.44.0-3.2.hum1 |
buildah-testsRed Hat:hummingbird:1 From an advisory covering 2 CVEs |
before 0:1.44.0-3.2.hum1 | 0:1.44.0-3.2.hum1 |
podmanRed Hat:hummingbird:1 From an advisory covering 3 CVEs |
before 0:6.0.2-2.1.hum1 | 0:6.0.2-2.1.hum1 |
podman-dockerRed Hat:hummingbird:1 From an advisory covering 3 CVEs |
before 0:6.0.2-2.1.hum1 | 0:6.0.2-2.1.hum1 |
podman-machineRed Hat:hummingbird:1 From an advisory covering 3 CVEs |
before 0:6.0.2-2.1.hum1 | 0:6.0.2-2.1.hum1 |
podman-remoteRed Hat:hummingbird:1 From an advisory covering 3 CVEs |
before 0:6.0.2-2.1.hum1 | 0:6.0.2-2.1.hum1 |
podman-testsRed Hat:hummingbird:1 From an advisory covering 3 CVEs |
before 0:6.0.2-2.1.hum1 | 0:6.0.2-2.1.hum1 |
podmanshRed Hat:hummingbird:1 From an advisory covering 3 CVEs |
before 0:6.0.2-2.1.hum1 | 0:6.0.2-2.1.hum1 |
trivyRed Hat:hummingbird:1 From an advisory covering 3 CVEs |
before 0:0.72.0-0.1.2.hum1 | 0:0.72.0-0.1.2.hum1 |
buildahRed Hat:hummingbird:1 From an advisory covering 4 CVEs |
before 0:1.45.0-2.hum1 | 0:1.45.0-2.hum1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-15788 is a medium vulnerability (CVSS 5.6) in Moby Buildkit, published July 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 35th percentile. No source names a fixed version.
References
github.com/moby/buildkit/security/advisories/GHSA-388v-wmr2-g2v2
docs.bell-sw.com/security/cves/CVE-2026-15788
nvd.nist.gov/vuln/detail/CVE-2026-15788
access.redhat.com/errata/RHSA-2026:43122
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images.redhat.com
security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_43122.json
bugzilla.redhat.com/show_bug.cgi?id=2502989
cve.org/CVERecord?id=CVE-2026-15788
go.dev/cl/794100
pkg.go.dev/vuln/GO-2026-5970