CVE-2026-89011

isomorphic-git before 1.42.0 contains a prototype pollution vulnerability in the getRemoteInfo function that allows a malicious Git server operator to pollute Object.prototype by advertising crafted ref names containing '__proto__' path segments during ref negotiation. Attackers controlling a Git server can advertise a specially crafted ref such as '__proto__/corsProxy' to reroute all subsequent network operations through an attacker-controlled proxy, causing isomorphic-git to invoke the victim's onAuth callback and transmit credentials to the attacker when the victim calls getRemoteInfo with an attacker-supplied URL.

CVSS v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/isomorphic-git/isomorphic-git/commit/b3db111885230bac9a648e0a2312c65ca66f76eb
https://github.com/isomorphic-git/isomorphic-git/pull/2426
https://github.com/isomorphic-git/isomorphic-git/releases/tag/v1.42.0
https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-83vg-jxvh-fx76
https://www.vulncheck.com/advisories/isomorphic-git-prototype-pollution-via-getremoteinfo

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-10 20:17

Updated : 2026-09-11 21:17

NVD link : CVE-2026-89011

Mitre link : CVE-2026-89011

CVE.ORG link : CVE-2026-89011

JSON object : View

Products Affected

No product.

CWE

CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

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