CVE-2026-44293: Protobufjs Project Protobufjs

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated JavaScript for toObject conversion could include an unsafe expression derived from a schema-controlled bytes field default value. A crafted descriptor with a non-string default value for a bytes field could cause attacker-controlled code to be emitted into the generated conversion function. This vulnerability is fixed in 7.5.6 and 8.0.2.

Affected products

• Protobufjs Project Protobufjs: before 7.5.6 (fixed in 7.5.6); from 8.0.0, before 8.0.2 (fixed in 8.0.2)

Published 2026-05-13. Last modified 2026-09-09.