What is CVE-2026-44290?

CVE-2026-44290 is a high-severity vulnerability in Protobufjs Protobuf.js, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.5/10. Published 2026-05-13.

How severe is CVE-2026-44290?

High severity. CVSS v3 base score is 7.5 out of 10.

Prototype Pollution in Protobufjs Protobuf.js

CVE-2026-44290

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs allowed certain schema option paths to traverse through inherited object properties while applying options. A crafted protobuf sc…

Vulnerability class: Prototype Pollution

EPSS: 0.001 (27.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Protobufjs Protobuf.js — versions < 7.5.6, >= 8.0.0, < 8.0.2
Protobufjs_project Protobufjs

Weakness classification (CWE)

CWE-1321 — Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution)

References

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

Frequently asked questions

What is CVE-2026-44290?: CVE-2026-44290 is a high-severity vulnerability in Protobufjs Protobuf.js, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.5/10. Published 2026-05-13.
How severe is CVE-2026-44290?: High severity. CVSS v3 base score is 7.5 out of 10.