CVE-2026-39819

Invoking "go bug" follows symlinks in predictable temporary filenames in cmd/go

CVSS 5.3 MEDIUMEPSS 0.2%

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 5.3EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

07 May 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

The "go bug" command writes to two files with predictable names in the system temporary directory (for example, "/tmp"). An attacker with access to the temporary directory can create a symlink in one of these names, causing "go bug" to overwrite the target of the symlink.

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N

Affected products

Go toolchain · cmd/go

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References

https://go.dev/cl/763882 https://go.dev/issue/78584 https://groups.google.com/g/golang-announce/c/qcCIEXso47M https://pkg.go.dev/vuln/GO-2026-4978