CVE-2026-54271
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.
⚡ Watch CVE-2026-54271
Get an email if CVE-2026-54271 is added to CISA KEV, gains public exploit code, or a new advisory cites it — max one per day, one-click unsubscribe.
Exploitation outlook
- Low exploitation risk0.30% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all EPSS-scored CVEs.
Advisory coverage (1)
External references
Embed the live status
— this badge updates automatically when the KEV or exploit status changes. How to embed it →
[](https://www.csirts.com/cve/CVE-2026-54271)