CVE-2026-59877mediumCWE-835

CVE-2026-59877: medium-severity vulnerability in protobufjs protobuf.js

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

Published

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13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 5.3epss 0.4%
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
protobufjs · protobuf.js
Related CVEs — protobufjs protobuf.js

In the same product, most dangerous first.

CVE-2026-41242CRITICALprotobufjs has an arbitrary code execution issueEPSS 0.8%CVE-2026-44289HIGHprotobufjs: Denial of service through unbounded protobuf recursionEPSS 0.6%CVE-2026-44291HIGHprotobufjs: Code generation gadget after prototype pollutionEPSS 0.5%CVE-2026-48712HIGHprotobufjs: Denial of service through unbounded Any expansion during JSON conversionEPSS 0.5%CVE-2026-44294MEDIUMprotobufjs: Denial of service from crafted field names in generated codeEPSS 0.4%CVE-2026-44293HIGHprotobufjs: Code injection through bytes field defaults in generated toObject codeEPSS 0.4%