CVE-2026-59877CWE-835

protobufjs: Denial of Service via infinite loop in .proto option parsing

Medium · published July 8, 2026

CVSS v3.1
5.3
EPSS
0%
Percentile
29.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS v4.0
Not supplied
EPSS
0.00365 · 29.2th percentile
Weakness
CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')
Published
2026-07-08T15:28Z
EPSS history
Timeline
  • 08 JUL 15:28Z
    protobufjs: Denial of Service via infinite loop in .proto option parsing
    cvelistv5