CVE-2026-59877
Medium
Description
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 .proto schema that opens an option declaration and ends prematurely can cause parse, Root.load, or Root.loadSync to loop indefinitely. This issue is fixed in versions 7.6.5 and 8.6.6.
SeverityMedium
CVSS5.3
Exploit probability—
ProductProtobufjs
PublishedJul 8, 2026
First seenJul 8, 2026
Weakness typeCWE-835CWE-835
How to fix
Update
- protobufjs_project protobufjs7.6.5, 8.6.6 or later
- protobufjs7.6.5, 8.6.6 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| protobufjs_project protobufjs | v < 7.6.5, 8.0.0 ≤ v < 8.6.6 | 7.6.5, 8.6.6 |
| protobufjsnpm | 7.5.0 ≤ v < 7.6.5, 8.0.0 ≤ v < 8.6.6 | 7.6.5, 8.6.6 |
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