CVE-2026-63475

isomorphic-git: Circular symbolic references cause non-terminating resolution (DoS)

Published Nov 3, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
isomorphic-git is a pure JavaScript implementation of Git for Node.js and browsers. Prior to 1.38.6, isomorphic-git persists server-supplied circular symref= capabilities through updateRemoteRefs, and GitRefManager.resolve() follows the resulting loose symbolic references without a default depth limit or cycle detection. After a clone from a malicious or man-in-the-middle-controlled remote, operations such as log, status, checkout, and branch that resolve refs/remotes/origin/a or refs/remotes/origin/b do not terminate. The circular references remain on disk, leaving the repository unusable for the application and causing a persistent denial of service. This issue is fixed in version 1.38.6.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-96wc-2m84-2cj7 isomorphic-git: Circular symbolic references cause non-terminating resolution (DoS)
History
Type Values Removed Values Added
First Time appeared Isomorphic-git
Isomorphic-git isomorphic-git
Vendors & Products Isomorphic-git
Isomorphic-git isomorphic-git
Type Values Removed Values Added
Description isomorphic-git is a pure JavaScript implementation of Git for Node.js and browsers. Prior to 1.38.6, isomorphic-git persists server-supplied circular symref= capabilities through updateRemoteRefs, and GitRefManager.resolve() follows the resulting loose symbolic references without a default depth limit or cycle detection. After a clone from a malicious or man-in-the-middle-controlled remote, operations such as log, status, checkout, and branch that resolve refs/remotes/origin/a or refs/remotes/origin/b do not terminate. The circular references remain on disk, leaving the repository unusable for the application and causing a persistent denial of service. This issue is fixed in version 1.38.6.
Title isomorphic-git: Circular symbolic references cause non-terminating resolution (DoS)
Weaknesses CWE-674
CWE-835
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 3, 2026, 9:31 PM
Reserved
Jul 16, 2026, 9:37 PM
Status
Deferred
Published
Nov 3, 2026, 8:18 PM
Modified
Nov 3, 2026, 10:19 PM
Severity
Moderate
Public date
Nov 3, 2026, 7:45 PM