Integer overflow in Golang.org/x/sys Golang.org/x/sys/windows

CVE-2026-39824

NewNTUnicodeString does not check for string length overflow. When provided with a string that overflows the maximum size of a NTUnicodeString (a 16-bit number of bytes), it returns a truncated string rather than an error.

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (4.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-39824: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-39824?
CVE-2026-39824 is a low-severity vulnerability in Golang.org/x/sys Golang.org/x/sys/windows, classified under Integer Overflow or Wraparound. CVSS score: 3.3/10. Published 2026-05-22.
How severe is CVE-2026-39824?
Low severity. CVSS v3 base score is 3.3 out of 10.