isomorphic-git < 1.42.0 Prototype Pollution via getRemoteInfo
Summary
| CVE | CVE-2026-89011 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-10 20:17:31 UTC |
| Updated | 2026-09-10 20:17:31 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 7.1 HIGH from [email protected]
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
Problem Types: CWE-1321 | CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7.1 | HIGH | 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/C... |
| 4.0 | CNA | CVSS | 7.1 | HIGH | 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 |
| 3.1 | [email protected] | Primary | 7.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N |
| 3.1 | CNA | CVSS | 7.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
PassiveConfidentiality
HighIntegrity
LowAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Isomorphic-git | Isomorphic-git | affected 1.42.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/isomorphic-git/isomorphic-git/commit/b3db111885230bac9a648e0a... | [email protected] | github.com | |
| github.com/isomorphic-git/isomorphic-git/pull/2426 | [email protected] | github.com | |
| github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-83vg-j... | [email protected] | github.com | |
| www.vulncheck.com/advisories/isomorphic-git-prototype-pollution-via-getremoteinfo | [email protected] | www.vulncheck.com | |
| github.com/isomorphic-git/isomorphic-git/releases/tag/v1.42.0 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Isabel Mill (en)
CNA: VulnCheck (en)
There are currently no legacy QID mappings associated with this CVE.