Summary
A previous fix for unsafe name handling in pbjs static / static-module code generation was incomplete. Affected versions of protobufjs-cli could still emit unsafe JavaScript references when generating static output from crafted JSON descriptor input. The common case of parsing schemas from .proto files is not affected.
This is a bypass of GHSA-6r35-46g8-jcw9 / CVE-2026-44295.
Impact
An attacker who can provide or influence pre-parsed JSON descriptors passed to pbjs static code generation may be able to cause generated JavaScript output to contain attacker-controlled code.
The injected code may execute if the generated file is later executed or imported and an affected generated API path is invoked.
Preconditions
- The application or build process must run
pbjs static code generation on a pre-parsed JSON descriptor influenced by an attacker.
- The generated JavaScript file must subsequently be executed or imported.
- An affected generated API path must be invoked.
Workarounds
Do not run affected versions of pbjs static or static-module generation on untrusted JSON descriptors. If untrusted JSON descriptors must be accepted, validate descriptor-derived names before code generation and reject names that could not have been produced by parsing a valid .proto file. Running code generation in an isolated environment can reduce impact.
References
Summary
A previous fix for unsafe name handling in
pbjsstatic / static-module code generation was incomplete. Affected versions ofprotobufjs-clicould still emit unsafe JavaScript references when generating static output from crafted JSON descriptor input. The common case of parsing schemas from.protofiles is not affected.This is a bypass of GHSA-6r35-46g8-jcw9 / CVE-2026-44295.
Impact
An attacker who can provide or influence pre-parsed JSON descriptors passed to
pbjsstatic code generation may be able to cause generated JavaScript output to contain attacker-controlled code.The injected code may execute if the generated file is later executed or imported and an affected generated API path is invoked.
Preconditions
pbjsstatic code generation on a pre-parsed JSON descriptor influenced by an attacker.Workarounds
Do not run affected versions of
pbjsstatic or static-module generation on untrusted JSON descriptors. If untrusted JSON descriptors must be accepted, validate descriptor-derived names before code generation and reject names that could not have been produced by parsing a valid.protofile. Running code generation in an isolated environment can reduce impact.References