Google Go up to 1.25.7/1.26.0 os File.ReadDir/File.Readdir race condition

Summaryinfo

A vulnerability described as problematic has been identified in Google Go up to 1.25.7/1.26.0. Affected by this issue is the function File.ReadDir/File.Readdir of the component os. Such manipulation leads to race condition. This vulnerability is uniquely identified as CVE-2026-27139. The attack can be launched remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Google Go up to 1.25.7/1.26.0 and classified as problematic. Affected by this issue is the function File.ReadDir/File.Readdir of the component os. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-363. The product checks the status of a file or directory before accessing it, which produces a race condition in which the file can be replaced with a link before the access is performed, causing the product to access the wrong file. Impacted is confidentiality, integrity, and availability. CVE summarizes:

On Unix platforms, when listing the contents of a directory using File.ReadDir or File.Readdir the returned FileInfo could reference a file outside of the Root in which the File was opened. The impact of this escape is limited to reading metadata provided by lstat from arbitrary locations on the filesystem without permitting reading or writing files outside the root.

The advisory is shared for download at groups.google.com. This vulnerability is handled as CVE-2026-27139 since 02/17/2026. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 04/01/2026).

The vulnerability scanner Nessus provides a plugin with the ID 301396 (Linux Distros Unpatched Vulnerability : CVE-2026-27139), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.25.8 or 1.26.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (301396) and CERT Bund (WID-SEC-2026-0548). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Amazon Linux 2
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Golang Go

Productinfo

Type

• Programming Language Software

Vendor

• Google

Name

• Go

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21
• 1.22
• 1.23
• 1.24
• 1.25
• 1.25.0
• 1.25.1
• 1.25.2
• 1.25.3
• 1.25.4
• 1.25.5
• 1.25.6
• 1.25.7
• 1.26.0

License

• open-source

Website

• Vendor: https://www.google.com/

CPE 2.3info

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

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