protobufjs protobuf.js up to 8.4.x allocation of resources

Summaryinfo

A vulnerability was found in protobufjs protobuf.js up to 8.4.x. It has been classified as problematic. Affected by this issue is some unknown functionality. This manipulation causes allocation of resources. The identification of this vulnerability is CVE-2026-54270. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in protobufjs protobuf.js up to 8.4.x. It has been declared as problematic. Affected by this vulnerability is an unknown code block. 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:

protobufjs compiles protobuf definitions into JavaScript (JS) functions. From 8.2.0 to 8.4.2, protobufjs preserved unknown wire elements in message.$unknowns and did not provide a decode-time option to discard unknown fields before retaining them. A crafted protobuf payload containing many unknown fields could therefore cause a decoded message to retain substantially more memory than the input size would suggest, even when unknown-field round-tripping is not needed. protobufjs 8.5.0 added the relevant decode-time options, allowing applications that decode untrusted protobuf data to disable unknown-field retention during decode. protobufjs 8.6.2 flips the default so unknown fields are discarded unless explicitly opted into.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-54270 since 06/12/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 8.5.0 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• JavaScript Library

Vendor

• protobufjs

Name

• protobuf.js

Version

• 8.0
• 8.1
• 8.2
• 8.3
• 8.4

Website

• Product: https://github.com/protobufjs/protobuf.js/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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