Prototype pollution in protobuf.js - CVE-2026-44290
Published: May 12, 2026
Vulnerability identifier: #VU131165
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-44290
CWE-ID: CWE-1321
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: protobuf.js
Affected software:
protobuf.js
protobuf.js
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper control of prototype-based property paths in protobufjs reflection APIs when parsing attacker-controlled protobuf schemas or JSON descriptors. A remote attacker can provide a specially crafted schema or descriptor to cause a denial of service.
Applications that only decode untrusted protobuf message payloads using bundled, generated, or otherwise trusted schemas are not directly affected.
How to mitigate CVE-2026-44290
Install security update from vendor's website.