# CVE-2026-89011

## Summary

- **CVE ID:** CVE-2026-89011
- **Severity:** HIGH
- **CVSS Score:** 7.1 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-1321
- **Published:** Sep 10, 2026
- **Last Modified:** Sep 10, 2026

## Description

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.

## Affected Products

- isomorphic-git — isomorphic-git (0)

## References

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

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._