How severe is CVE-2026-15788?

CVE-2026-15788 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-15788 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-15788?

CVE-2026-15788 affects Mobyproject Buildkit. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-15788?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-15788 published?

CVE-2026-15788 was published on 2026-07-20 and last updated on 2026-08-05.

CVE-2026-15788

CVE-2026-15788 is a high-severity vulnerability in Mobyproject Buildkit with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-59.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 5.6
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-59
Affected product: Mobyproject Buildkit
Published: 2026-07-20
Last modified: 2026-08-05

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.

Frequently asked questions

What is CVE-2026-15788?: 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.
How severe is CVE-2026-15788?: CVE-2026-15788 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-15788 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-15788?: CVE-2026-15788 affects Mobyproject Buildkit. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-15788?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-15788 published?: CVE-2026-15788 was published on 2026-07-20 and last updated on 2026-08-05.

References

https://github.com/moby/buildkit/security/advisories/GHSA-388v-wmr2-g2v2

Affected products (1)

cpe:2.3:a:mobyproject:buildkit:*:*:*:*:*:*:*:*

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