Prototype Pollution in Protobufjs Protobuf.js

CVE-2026-44292

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated message constructors copied enumerable properties from a provided properties object without filtering the __proto__ key…

Vulnerability class: Prototype Pollution

EPSS: 0.001 (24.2th 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:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44292?
CVE-2026-44292 is a medium-severity vulnerability in Protobufjs Protobuf.js, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 5.3/10. Published 2026-05-13.
How severe is CVE-2026-44292?
Medium severity. CVSS v3 base score is 5.3 out of 10.