GHSA-j3f2-48v5-ccww
protobufjs: Denial of Service via infinite loop in .proto option parsing
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | protobufjs | >= 7.5.0, < 7.6.5 | 7.6.5 |
| npm | protobufjs | >= 8.0.0, < 8.6.6 | 8.6.6 |
Details
As written in the advisory (Markdown source, shown as plain text).
## Summary
protobufjs parsed option names by advancing through schema tokens until it reached an `=` token, without checking for end of input. A crafted `.proto` schema that opens an option declaration but ends prematurely could cause the option parser to loop without ever terminating.
This affects the reflection parsing path (`parse`, `Root.load`, `Root.loadSync`).
## Impact
An attacker who can provide or influence `.proto` schema text parsed by an application may be able to cause the parsing call to never return. Because Node.js is single-threaded, the blocked event loop prevents all other work in the process, resulting in a denial of service that persists until the process is externally terminated.
Applications that only encode or decode protobuf binary data with trusted schemas are not directly affected.
## Preconditions
- The application must parse `.proto` schema text influenced by an attacker.
- The schema must be parsed through APIs such as `parse`, `Root.load`, or `Root.loadSync`.
- The crafted input must begin an option declaration that ends before its `=` assignment.
## Workarounds
Do not parse `.proto` schemas from untrusted sources with affected versions. If untrusted schema text must be accepted, isolate parsing in a process or worker that can be safely terminated and bound it with a timeout, so a non-returning parse call cannot deny service to the rest of the application.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-j3f2-48v5-ccww
- https://nvd.nist.gov/vuln/detail/CVE-2026-59877
- https://github.com/protobufjs/protobuf.js/pull/2352
- https://github.com/protobufjs/protobuf.js/commit/10fba6d54815ceecca8a06b9a6db490c8f5d2217
- https://github.com/protobufjs/protobuf.js/commit/fa5c73add738ceb471e74da8cc2f3727c3d0a69f
- https://github.com/protobufjs/protobuf.js
- https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v7.6.5
- https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v8.6.6