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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 7.1 HIGHCVSS: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/M
- EPSS
- 0.26% probability · 18th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-1321
- Source
- disclosure@vulncheck.com
References
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.