CVE-2026-39822 | On Unix systems, opening a file in an os.Root improperly fol… | CVSS 7.8 HIGH

Description

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.

Metadata

CVE ID: CVE-2026-39822
State: PUBLISHED
Assigner: Go
Reserved: 2026-04-07 18:13 UTC
Published: 2026-07-08 15:46 UTC
Last updated: 2026-07-08 19:39 UTC
Primary CWE: CWE-61
CWE-61 UNIX Symbolic Link (Symlink) Following
Vendor / Product: Go standard library / os
Sources: cve.org · NVD

Severity & Metrics

7.8 HIGH CVSS 3.1

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

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
Go standard library	os	—	0 < 1.25.12, 1.26.0-0 < 1.26.5, 1.27.0-0 < 1.27.0-rc.2

Weakness (CWE)

CWE	Source	Description
—	cna	CWE-61: UNIX Symbolic Link (Symlink) Following
CWE-61	adp	CWE-61 UNIX Symbolic Link (Symlink) Following

CVSS scores (1)

Score	Severity	Version	Source	Vector
7.8	HIGH	3.1	adp	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References (4)