CVE-2026-59877: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') in protobufjs protobuf.js
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.
AI Analysis
Technical Summary
The protobufjs library, which compiles protobuf definitions into JavaScript functions, has a vulnerability (CWE-835) in versions before 7.6.5 and 8.6.6. When parsing option names, the parser advances through tokens until it finds an '=' token but does not verify if the input has ended. A crafted .proto schema that opens an option declaration and ends prematurely can cause the parse functions (parse, Root.load, Root.loadSync) to enter an infinite loop. This vulnerability has a CVSS 3.1 base score of 5.3, indicating a medium severity denial-of-service impact due to an infinite loop causing resource exhaustion. The issue is resolved in protobuf.js versions 7.6.5 and 8.6.6.
Potential Impact
An attacker can cause the protobuf.js parser to enter an infinite loop by providing a specially crafted .proto schema with an incomplete option declaration. This results in denial of service by consuming CPU resources indefinitely during parsing. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade protobuf.js to version 7.6.5 or later, or 8.6.6 or later, where this issue is fixed. No other mitigation is indicated. Patch status is confirmed fixed in these versions.
CVE-2026-59877: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') in protobufjs protobuf.js
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.
CVSS v3.1
Score 5.3medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The protobufjs library, which compiles protobuf definitions into JavaScript functions, has a vulnerability (CWE-835) in versions before 7.6.5 and 8.6.6. When parsing option names, the parser advances through tokens until it finds an '=' token but does not verify if the input has ended. A crafted .proto schema that opens an option declaration and ends prematurely can cause the parse functions (parse, Root.load, Root.loadSync) to enter an infinite loop. This vulnerability has a CVSS 3.1 base score of 5.3, indicating a medium severity denial-of-service impact due to an infinite loop causing resource exhaustion. The issue is resolved in protobuf.js versions 7.6.5 and 8.6.6.
Potential Impact
An attacker can cause the protobuf.js parser to enter an infinite loop by providing a specially crafted .proto schema with an incomplete option declaration. This results in denial of service by consuming CPU resources indefinitely during parsing. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade protobuf.js to version 7.6.5 or later, or 8.6.6 or later, where this issue is fixed. No other mitigation is indicated. Patch status is confirmed fixed in these versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-07T15:41:53.607Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e73c3c9d9e3dbe360460c
Added to database: 07/08/2026, 15:58:59 UTC
Last enriched: 07/08/2026, 16:14:01 UTC
Last updated: 08/22/2026, 10:52:10 UTC
Views: 100
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