SB20261110284 - Prototype pollution in isomorphic-git

CSH
CYBERSECURITY HELP
Sign In REGISTER

Main Vulnerability Database SB20261110284

SB20261110284 - Prototype pollution in isomorphic-git

Published: November 10, 2026

Security Bulletin ID SB20261110284
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: CVE-2026-89011)

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

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to pollute shared object prototypes, redirect subsequent Git requests, and steal authentication credentials.

The vulnerability exists due to prototype pollution in isomorphic-git's getRemoteInfo when unvalidated server-advertised ref segments traverse inherited properties of plain objects. A remote attacker can advertise "http://attacker/proxy __proto__/corsProxy", induce a victim to query the malicious repository, and issue a 401 challenge through the injected proxy during subsequent requests to capture credentials supplied by onAuth.


Remediation

Install update from vendor's website.

References