Resource exhaustion in Protobufjs Protobuf.js

CVE-2026-54270

protobufjs compiles protobuf definitions into JavaScript (JS) functions. From 8.2.0 to 8.4.2, protobufjs preserved unknown wire elements in message.$unknowns and did not provide a decode-time option to discard unknown fields before retaini…

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-54270?
CVE-2026-54270 is a medium-severity vulnerability in Protobufjs Protobuf.js, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2026-06-22.
How severe is CVE-2026-54270?
Medium severity. CVSS v3 base score is 5.3 out of 10.