Go standard library os up to 1.25.11/1.26.4 Root Open symlink

Summaryinfo

A vulnerability described as problematic has been identified in Go standard library os up to 1.25.11/1.26.4. Impacted is the function Open of the component Root. The manipulation results in symlink. This vulnerability is known as CVE-2026-39822. Attacking locally is a requirement. No exploit is available.

Detailsinfo

A vulnerability classified as problematic has been found in Go standard library os up to 1.25.11/1.26.4. Affected is the function Open of the component Root. The manipulation with an unknown input leads to a symlink vulnerability. CWE is classifying the issue as CWE-61. The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files. This is going to have an impact on confidentiality. CVE summarizes:

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.

The advisory is shared for download at go.dev. This vulnerability is traded as CVE-2026-39822 since 04/07/2026. The exploitability is told to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 325627 (Linux Distros Unpatched Vulnerability : CVE-2026-39822), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.25.12, 1.26.5 or 1.27.0-rc.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (325627). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Software Library

Vendor

• Go standard library

Name

• os

Version

• 1.25.0
• 1.25.1
• 1.25.2
• 1.25.3
• 1.25.4
• 1.25.5
• 1.25.6
• 1.25.7
• 1.25.8
• 1.25.9
• 1.25.10
• 1.25.11
• 1.26.0
• 1.26.1
• 1.26.2
• 1.26.3
• 1.26.4

CPE 2.3info

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CPE 2.2info

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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