CVE-2026-54270
protobufjs: Memory amplification from preserved unknown fields in binary decode
Description
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.
INFO
Published Date :
June 22, 2026, 6:16 p.m.
Last Modified :
Oct. 25, 2026, 11:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update protobufjs to version 8.6.2 or later.
- Configure decoding to discard unknown fields if using older versions.
- Enable unknown field retention only when necessary.
Public PoC/Exploit Available at Github
CVE-2026-54270 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54270.
| URL | Resource |
|---|---|
| https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-94rc-8x27-4472 | Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54270 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54270
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Dockerfile
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54270 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54270 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: protobuf.js de protobufjs, Description: protobufjs compila definiciones de protobuf en funciones de JavaScript (JS). Desde la versión 8.2.0 hasta la 8.4.2, protobufjs conservaba elementos de cable desconocidos en message.$unknowns y no proporcionaba una opción en tiempo de decodificación para descartar campos desconocidos antes de retenerlos. Una carga útil de protobuf manipulada que contenía muchos campos desconocidos podría, por lo tanto, causar que un mensaje decodificado retuviera sustancialmente más memoria de lo que sugeriría el tamaño de entrada, incluso cuando no es necesario el viaje de ida y vuelta de campos desconocidos. protobufjs 8.5.0 añadió las opciones relevantes en tiempo de decodificación, permitiendo que las aplicaciones que decodifican datos protobuf no confiables deshabiliten la retención de campos desconocidos durante la decodificación. protobufjs 8.6.2 invierte el valor predeterminado de modo que los campos desconocidos se descartan a menos que se opte explícitamente por ellos. -
Initial Analysis by [email protected]
Jun. 24, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:protobufjs_project:protobufjs:*:*:*:*:*:node.js:*:* versions from (including) 8.2.0 up to (excluding) 8.5.0 Added Reference Type GitHub, Inc.: https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-94rc-8x27-4472 Types: Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 23, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-54270', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-23T14:47:41.353008Z'} -
New CVE Received by [email protected]
Jun. 22, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'protobufjs', 'product': 'protobuf.js', 'versions': [{'status': 'affected', 'version': '>=8.2.0, < 8.5.0'}]}] Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-770 Added Reference https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-94rc-8x27-4472