CVE-2026-89011isomorphic-git < 1.42.0 Prototype Pollution via getRemoteInfo
- 7.1HighCVSS base score
- 0.44%Exploitation in 30 daysEPSS · top 61% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By VulnCheck
Published
- 59 days later
· 59 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | High7.1 | 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 |
| VulnCheckCNA (assigner) | 3.1 | High7.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N |
| NVDNVD · Deferred | 4.0 | High7.1 | 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 |
- EPSS (exploitation in 30 days)
- 0.44% · top 61% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Affected products
isomorphic-git · isomorphic-git
- affected < 1.42.0
References
References5
- GitHub Security Advisory (GHSA-83vg-jxvh-fx76) (opens in a new tab)vendor-advisory
- isomorphic-git 1.42.0 Release Notes (opens in a new tab)release-notes
- Pull Request (opens in a new tab)issue-trackingpatch
- Patch Commit (opens in a new tab)patch
- https://www.vulncheck.com/advisories/isomorphic-git-prototype-pollution-via-getremoteinfo (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-75710 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-89011)Record last updated .