Vulnerability in Protobufjs Protobuf.js

CVE-2026-59877

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.6.5 and 8.6.6, protobufjs parsed option names by advancing through schema tokens until reaching an = token without checking for end of input, so a crafted…

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-2026-59877?
CVE-2026-59877 is a medium-severity vulnerability in Protobufjs Protobuf.js, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.3/10. Published 2026-07-08.
How severe is CVE-2026-59877?
Medium severity. CVSS v3 base score is 5.3 out of 10.