CVE-2026-59876

Published Jul 8, 2026

Last updated a month ago

CVSS medium 4.8

Overview

Description
protobufjs compiles protobuf definitions into JavaScript (JS) functions. From 8.2.0 until 8.6.5, the protobufjs Text Format extension parsed string-keyed map entries using ordinary property assignment, allowing a map entry with key __proto__ to change the prototype of the returned map object instead of creating an own map entry in protobufjs/ext/textformat. This issue is fixed in version 8.6.5.
Source
security-advisories@github.com
NVD status
Analyzed
Products
protobufjs

Risk scores

CVSS 3.1

Type
Primary
Base score
4.8
Impact score
2.5
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-1321

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.6.5 and 8.6.6, protobufjs parsed option names by advancing through schema tokens until reaching an = token without checking for end of input, so a crafted .proto schema that opens an option declaration and ends prematurely can cause parse, Root.load, or Root.loadSync to loop indefinitely. This issue is fixed in versions 7.6.5 and 8.6.6.•CVE-2026-59877
  2. 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.•CVE-2026-54270
  3. protobufjs compiles protobuf definitions into JavaScript (JS) functions. 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. The known affected names are fields named hasOwnProperty, field or oneof names such as $type when loaded through protobufjs JSON/reflection descriptors, and service methods whose generated helper name is rpcCall. When affected message or service types were used, protobufjs could read schema-controlled data where it expected an own-property helper, reflected type metadata, or the base RPC helper. This could cause deterministic exceptions or recursive calls in affected decode post-checks, verification, object conversion, reflected JSON serialization, or protobufjs RPC helper invocation. This vulnerability is fixed in 8.6.0 and 7.6.3.•CVE-2026-54269
  4. protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.6.1 and 8.4.1, protobufjs could recurse without a depth limit while converting decoded messages to plain objects or JSON. This affected generated toObject() conversion and the custom google.protobuf.Any JSON conversion path. A crafted protobuf binary payload containing deeply nested Any values could cause the JavaScript call stack to be exhausted during conversion to JSON. This vulnerability is fixed in 7.6.1 and 8.4.1.•CVE-2026-48712
  5. protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.8 and 8.2.0, protobufjs could recurse without a depth limit while expanding nested JSON descriptors through Root.fromJSON() and Namespace.addJSON(). A crafted JSON descriptor with deeply nested namespace definitions could cause the JavaScript call stack to be exhausted during descriptor loading. This vulnerability is fixed in 7.5.8 and 8.2.0.•CVE-2026-45740

References

Sources include official advisories and independent security research.