JavaScript Code Injection in Protobuf.js by Protobuf Definitions
CVE-2026-44293

7.7HIGH

Key Information:

Vendor

Protobufjs

Status
Protobuf.js
Vendor
CVE Published:
13 May 2026

What is CVE-2026-44293?

Protobuf.js, a library for converting protocol buffers into JavaScript functions, has a vulnerability in its toObject conversion method prior to versions 7.5.6 and 8.0.2. Due to the way it handles schema-controlled bytes fields, a crafted descriptor with a non-string default could lead to the generation of unsafe JavaScript code. If exploited, this could allow for the injection of attacker-controlled code into the generated conversion function, posing significant security risks. Users are strongly encouraged to upgrade to the latest versions to mitigate this vulnerability.

Affected Version(s)

protobuf.js < 7.5.6 < 7.5.6

protobuf.js >= 8.0.0, < 8.0.2 < 8.0.0, 8.0.2

References

https://github.com/protobufjs/protobuf.js/security/adviso...
x_refsource_CONFIRM

CVSS V4

Score:
7.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.