Go encoding/xml up to 1.25.12/1.26.5 DecodeElement allocation of resources

Summaryinfo

A vulnerability has been found in Go encoding and xml up to 1.25.12/1.26.5 and classified as problematic. This vulnerability affects the function DecodeElement. Performing a manipulation results in allocation of resources. This vulnerability is identified as CVE-2026-56859. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Go encoding and xml up to 1.25.12/1.26.5. It has been classified as problematic. This affects the function DecodeElement. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as 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. This is going to have an impact on availability. The summary by CVE is:

Previously, DecodeElement would reset the depth counter causing it to never fire; this could lead to stack exhaustion.

It is possible to read the advisory at go.dev. This vulnerability is uniquely identified as CVE-2026-56859 since 06/23/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. 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

• encoding
• xml

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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Entryinfo

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

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