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Fencer Vulns
high 7.1

CVE-2026-89011 json

isomorphic-git < 1.42.0 Prototype Pollution via getRemoteInfo

published 2026-09-10 59 d ago modified 2026-11-08 25 h ago also EUVD-2026-75710

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Patch / fix

  • isomorphic-git isomorphic-git 1.42.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-89011 updated cvss 7.1

isomorphic-git: isomorphic-git: Information disclosure via prototype pollution in getRemoteInfo function.

  • Red Hat Ansible Automation Platform 2.1 ansible-automation-platform/automation-portal 1790254963
    fixed: vendor fix RHSA-2026:72712
  • Red Hat Ansible Automation Platform 2.2 ansible-automation-platform/automation-portal 1790256405, ansible-automation-platform/bootc-automation-portal-rhel9 1792641102
    fixed: vendor fix RHSA-2026:72722
  • Red Hat Developer Hub 1.10 rhdh/rhdh-hub-rhel9 1791311495, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator-backend 1791251282, rhdh/red-hat-developer-hub-backstage-plugin-scaffolder-backend-module-orchestrator 1791249640
    fixed: vendor fix RHSA-2026:76788
  • Red Hat Developer Hub 1.10 rhdh/rhdh-rhel9-operator 1791219676, rhdh/rhdh-operator-bundle 1791315788, rhdh/rhdh-must-gather-rhel9 1788278523, rhdh/rhdh-rag-content-rhel9 1791168570, rhdh/red-hat-developer-hub-backstage-plugin-lightspeed 1791242743, rhdh/red-hat-developer-hub-backstage-plugin-orchestrator 1791250003, +3 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
58 d ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 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
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
CNA 4.0 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • isomorphic-git isomorphic-git

Classification

Weakness
  • CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.