CVE-2026-39817: Golang Go

Medium severity, CVSS 5.9. EPSS: 0.2% chance of exploitation in the next 30 days.

The "go tool pack" subcommand (usually used only by the compiler as an internal tool with known-good inputs) does not sanitize output filenames. Extracting a malicious archive file with the "pack" subcommand can write files to arbitrary locations on the filesystem.

Affected products

• Golang Go: before 1.25.10 (fixed in 1.25.10); from 1.26.0, before 1.26.3 (fixed in 1.26.3)

Published 2026-05-07. Last modified 2026-06-17.