Go nethttp up to 1.25.12/1.26.5 allocation of resources

Summaryinfo

A vulnerability identified as problematic has been detected in Go nethttp up to 1.25.12/1.26.5. The affected element is an unknown function. This manipulation causes allocation of resources. This vulnerability appears as CVE-2026-56853. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Go nethttp up to 1.25.12/1.26.5. It has been declared as problematic. Affected by this vulnerability is some unknown functionality. The manipulation with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. As an impact it is known to affect availability. The summary by CVE is:

When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.

It is possible to read the advisory at go.dev. This vulnerability is known as CVE-2026-56853 since 06/23/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 341090 (RockyLinux 9 : golang (RLSA-2026:60304)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.25.13, 1.26.6 or 1.27.0-rc.3 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (341090) and CERT Bund (WID-SEC-2026-2850). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

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

Productinfo

Vendor

• Go

Name

• nethttp

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
• 1.25.12
• 1.26.0
• 1.26.1
• 1.26.2
• 1.26.3
• 1.26.4
• 1.26.5

CPE 2.3info

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CPE 2.2info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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