9.8

CVE-2026-56857: go standard library internal/syscall/windows

CVSS: 9.8v3.1CriticalAwaiting analysis
AliasesUBUNTU-CVE-2026-56857CGA-222r-qj2p-cf8pCGA-226w-m3f2-q8v4
Published 08-10-2026Last modified 09-10-2026
Open JSON

Vulnerability summary

CVE-2026-56857 is a critical (CVSS 9.8) vulnerability in go standard library internal/syscall/windows. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 41.3% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.49%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 9 · Related 9
OPENSUSE-SU-2026:12093-1OPENSUSE-SU-2026:12101-1OPENSUSE-SU-2026:12112-1OPENSUSE-SU-2026:22093-1OPENSUSE-SU-2026:22095-1SUSE-SU-2026:24237-1

Timeline

  1. 08-10-2026
    PublishedVulnerability first disclosed.
  2. 09-10-2026
    Last modifiedVulnerability information updated.

Description

On Windows, when the target of Root.Mkdir or Root.MkdirAll is a junction pointing to an empty location, the operation can create a directory at the junction target even when that target is located outside the root. This only applies to operations where the last path component is a junction (path/to/junction, but not path/junction/target).

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.49%

Chance of exploitation in the next 30 days

Percentile

41%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

09-10-202621-10-2026
EPSS score
0.49%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard200 products
  • aactl< 0.4.12-r79
  • access-log-exporter-fipsAll versions (No fix recorded)
  • acm-controller-fipsAll versions (No fix recorded)
  • actions-runner-controllerAll versions (No fix recorded)
  • actions-runner-controller-fipsAll versions (No fix recorded)

1 vendor · 200 products · Showing 200 of 4054. Use Open JSON for the complete list.

References

8 links