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.
History

Mon, 29 Jun 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Low


Wed, 24 Jun 2026 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Protobuf
Protobuf protobuf
Vendors & Products Protobuf
Protobuf protobuf

Tue, 23 Jun 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 22 Jun 2026 17:30:00 +0000

Type Values Removed Values 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.
Title protobufjs: Memory amplification from preserved unknown fields in binary decode
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-06-22T16:19:20.449Z

Updated: 2026-06-23T16:09:51.638Z

Reserved: 2026-06-12T17:13:32.279Z

Link: CVE-2026-54270

cve-icon Vulnrichment

Updated: 2026-06-23T14:47:45.537Z

cve-icon NVD

No data.

cve-icon Redhat

Severity : Low

Publid Date: 2026-06-22T16:19:20Z

Links: CVE-2026-54270 - Bugzilla