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TI-2026-13282 Aliases CVE-2026-15788

WCOW cache mount source selector resolves NTFS junctions outside of cache root

Priority LOW 25CWE-59Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Active
Attack complexity
Low
Attack requirements
Present
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-59 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00411 35th percentileScored 2026-11-07
Fix Fixed BuildKit (moby): 0.31.2Red Hat: 4 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
mobyBuildKitbefore 0.31.20.31.2Patch availableCNA
  • BuildKit Vendormoby Affected before 0.31.2 Fixed in 0.31.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mobyproject:buildkit:*:*:*:*:*:*:*:*before 0.31.2VulnerableMobyproject
  • cpe:2.3:a:mobyproject:buildkit:*:*:*:*:*:*:*:* Versions before 0.31.2 Vulnerable ·Mobyproject

Remediation

  • Fix · CNA BuildKit (moby) Fixed in 0.31.2

Red Hat 4 advisories

  • RHSA-2026:51065 Released 2026-08-06 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images buildah-2:1.45.0-2.hum1@aarch64, buildah-2:1.45.0-2.hum1@src, buildah-2:1.45.0-2.hum1@x86_64
  • RHSA-2026:46988 Released 2026-07-27 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images trivy-0.72.0-0.1.2.hum1@aarch64, trivy-0.72.0-0.1.2.hum1@src, trivy-0.72.0-0.1.2.hum1@x86_64
  • RHSA-2026:44152 Released 2026-07-23 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images podman-5:6.0.2-2.1.hum1@aarch64, podman-5:6.0.2-2.1.hum1@src, podman-5:6.0.2-2.1.hum1@x86_64 +10
Show 1 more Red Hat advisories
  • RHSA-2026:43122 Released 2026-07-22 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images buildah-2:1.44.0-3.2.hum1@aarch64, buildah-2:1.44.0-3.2.hum1@src, buildah-2:1.44.0-3.2.hum1@x86_64 +2

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Hardened ImagesFixed RHSA-2026:43122, RHSA-2026:44152, RHSA-2026:46988, RHSA-2026:51065

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-15788
  2. 2026-10-23 Affected versions changed · Red Hat

References

Advisory 1

  • TI-2026-14229 Tar extraction in moby/go-archive can write outside the destination directory via link following CVSS 4.0HIGH 7.1
  • TI-2021-12512 Moby HyperKit uninitialized memory use in virtio-sock pci_vtsock_proc_tx CVSS 3.1HIGH 7.1
  • TI-2024-27462 Moby authz zero length regression CVSS 3.1CRITICAL 10.0
  • TI-2024-15672 BuildKit interactive containers API does not validate entitlements check CVSS 3.1CRITICAL 9.8
  • TI-2024-15671 BuildKit possible host system access from mount stub cleaner CVSS 3.1CRITICAL 10.0
  • TI-2026-26365 Moby: AuthZ plugin bypass with oversized request body CVSS 3.1HIGH 8.8
See all 57 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences