CVE-2026-54270
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk21th percentile - higher than 21% of all known CVEs
Summary
Versions of protobufjs from 8.2.0 to 8.4.2 lacked options to discard unknown fields during decoding, which could lead to excessive memory usage by decoded messages. Version 8.5.0 introduced options to disable unknown field retention, and version 8.6.2 defaults to discarding unknown fields.
Risk Assessment
Organizations may experience performance issues and excessive memory consumption when applications decode untrusted protobuf data. This could lead to application crashes or service degradation.
Recommendation
It is recommended to upgrade to protobufjs version 8.6.2 or later to take advantage of the default unknown field discarding. Additionally, applications should be configured to use decoding options that disable unknown field retention.
Other vulnerabilities in protobufjs
See all- CVE-2026-41242Critical
A vulnerability in the protobufjs library allows arbitrary JavaScript code injection via 'type' fields in protobuf definitions. The code executes during object decoding. The issue is fixed in versions 8.0.1 and 7.5.5.
- CVE-2026-59877Medium
A vulnerability in the protobufjs library allows infinite looping when parsing specially crafted .proto files. The lack of end-of-input checking when processing options causes parse, Root.load, or Root.loadSync to loop indefinitely.
- CVE-2026-59876Medium
A vulnerability in the protobufjs library (versions 8.2.0 to 8.6.5) allows prototype pollution via parsing map entries in Text Format. An attacker can inject a map key named __proto__, which modifies the object prototype instead of creating a map entry.
- CVE-2026-54269Medium
In versions prior to 8.6.0 and 7.6.3, protobufjs accepted certain schema-derived names that could collide with properties used by protobufjs runtime helpers. This could lead to deterministic exceptions or recursive calls in various operations related to decoding and serialization.
- CVE-2026-44293High
protobufjs before versions 7.5.6 and 8.0.2 generates JavaScript for the toObject function that may include an unsafe expression from a schema-controlled bytes field default value. A crafted descriptor can lead to arbitrary code execution.
- CVE-2026-44289High
Protobufjs before versions 7.5.6 and 8.0.2 lacks a depth limit when decoding nested protobuf data. A crafted binary payload can exhaust the JavaScript call stack, causing a crash.
Original NVD description (English source)
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.