protobufjs: Denial of service through unbounded Any expansion during JSON conversion
- When
- Where
- Global (internet)
- Category
- cyber_advisory · npm
## Summary 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. ## Impact An attacker who can provide protobuf binary data decoded by an application may be able to crash the process or otherwise cause message conversion to fail with a stack overflow. This affects applications that decode untrusted protobuf input containing `google.protobuf.Any` values and then convert decoded messages to JSON or plain objects with JSON conversion enabled, for example through `JSON.stringify(message)`, `Message#toJSON()`, or `Type.toObject(message, { json: true })`. Applications that only decode and re-encode protobuf binary data without converting decoded messages to JSON are not directly affected by this issue. ## Preconditions * The application must decode protobuf binary data influenced by an attacker. * The application schema must include `google.protobuf.Any`, and the referenced `type_url` must resolve to a message type in the loaded protobuf root. * The application must convert the decoded message to JSON or a plain object through an affected conversion path. * The crafted input must contain deeply nested `Any` values that are expanded during conversion. ## Workarounds Avoid converting untrusted protobuf messages containing `google.protobuf.Any` values to JSON with affected versions. If immediate upgrade is not possible, reject or limit messages with deeply nested `Any` payloads at an outer protocol boundary where feasible, avoid JSON conversion of untrusted `Any` values, or isolate message conversion in a process that can be safely restarted.
Sources
- GitHub Advisory Database ↗ · first seen 2026-06-15 17:30 UTC
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