SB2026070402 - Prototype pollution in protobuf.js

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Main Vulnerability Database SB2026070402

SB2026070402 - Prototype pollution in protobuf.js

Published: July 4, 2026

Security Bulletin ID SB2026070402
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Prototype pollution (CVE-ID: N/A)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to disclose sensitive information or modify application behavior.

The vulnerability exists due to improperly controlled modification of object prototype attributes in the text format string-keyed map parser when parsing attacker-supplied protobuf text-format input. A remote attacker can provide a crafted map entry with the key __proto__ to disclose sensitive information or modify application behavior.

Only the optional Text Format extension is affected. Exploitation requires a target schema with a string-keyed map field, and impact depends on downstream application logic treating inherited properties on the returned map object as meaningful.


Remediation

Install update from vendor's website.

References