Vulnerability · Published Jun 22, 2026 · Assigned by GitHub_M
CVE-2026-54269protobufjs: Schema-derived names can shadow runtime-significant properties
Medium 5.3
In plain English
A medium-severity security flaw in protobuf.js from protobufjs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | protobufjs | 7.6.3 | GHSA-f38q-mgvj-vph7 |
| npm | protobufjs | 8.6.0 | GHSA-f38q-mgvj-vph7 |
| npm | protobufjs-cli | 2.5.1 | GHSA-f38q-mgvj-vph7 |
| npm | protobufjs-cli | 1.3.3 | GHSA-f38q-mgvj-vph7 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| protobufjs | protobuf.js | < 7.6.3>= 8.0.0, < 8.6.0 |
Weakness: CWE-674, CWE-754 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L