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.

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…

EPSS: 0.004 (32.9th percentile) — read the EPSS interpretation.

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

Protobufjs Protobuf.js — versions >=8.2.0, < 8.5.0
Protobufjs_project Protobufjs

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)

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.