CVE-2026-39819: The "go bug" command writes to two files with predictable names in the system temporary directory
Source GCVE Database
Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.26.3 or 1.25.10 when convenient.
Data as of 27 Oct 2026, 00:07 UTC
- Patch
- Available – fixed in 1.26.3, 1.25.10
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 7 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade cmd/go to 1.26.3 or 1.25.10.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Go toolchaincmd/go | Affected
| Fixed in
|
| Go toolchaincmd/go | Affected
| Fixed in
|
Gocmd/gopkg:golang/cmd/goOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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.