High 7.8Published Jul 8, 2026

CVE-2026-39822Root escape via symlink plus trailing slash in os

Updated under an hour ago (Oct 29, 2026, 1:50 AM ET)

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It affects Go standard library os and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Go standard library os

Exploited in the last 30 days

On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, 'root.Open("symlink/")' will open "symlink" even when "symlink" is a symbolic link pointing outside of the root.

CVSS: 7.8 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-61
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Go
NVD analysis: Analyzed
Record last updated: Jul 8, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Go standard library os go_standard_library:os (from the name)	before 1.25.12; from 1.26.0-0 before 1.26.5; 1.27.0-0 builds before 1.27.0-rc.2	CNA record
golang go golang:go	from 1.24.0 before 1.25.12; from 1.26.0 before 1.26.5; 1.27	NVD

References

References

https://go.dev/issue/79005	issue-tracking, patch
https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc	mailing-list, patch, vendor-advisory
https://go.dev/cl/797880	patch
https://pkg.go.dev/vuln/GO-2026-4970	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.