CVE-2026-39817
Extracting a malicious archive file with the "pack" subcommand can write files to arbitrary locations on the filesystem.
Does this matter?
Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 5.9 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N
- EPSS
- 0.17% probability · 6th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- golang/go
- Source
- security@golang.org
EPSS 0.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://go.dev/cl/767520Patch
- https://go.dev/issue/78778Issue Tracking
- https://groups.google.com/g/golang-announce/c/qcCIEXso47MIssue Tracking, Mailing List
- https://pkg.go.dev/vuln/GO-2026-4979Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.