isomorphic-git: Path traversal via a ".." tree-entry name writes files outside the working directory on clone/checkout
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
isomorphic-git is a pure JavaScript implementation of Git for Node.js and browsers. Prior to 1.38.6, isomorphic-git's tree parser in src/models/GitTree.js accepts a standalone .. tree-entry name because it rejects only path separators. During clone or checkout from a malicious or man-in-the-middle-controlled non-GitHub remote, nested .. entries can escape the working-tree root and write files at attacker-selected parent paths on any host-backed fs provider. The arbitrary file write can overwrite startup or configuration files and lead to code execution. GitHub-hosted trees are not a direct source because GitHub rejects .. entries during repository integrity checks. This issue is fixed in version 1.38.6.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| isomorphic-git | isomorphic-git | before 1.38.6 | 1.38.6 | Patch available | CNA |
- isomorphic-git Vendorisomorphic-git Affected before 1.38.6 Fixed in 1.38.6 Patch available CNA
Remediation
- Fix · CNA isomorphic-git (isomorphic-git) Fixed in 1.38.6
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Serverless | Affected | No fix yet: Fix deferred |
| Red Hat Developer Hub 1 | Affected | No fix yet: Fix deferred |
| Self-service automation portal 2 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-11-03 Threatist record created from CVE-2026-63478
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
- 2026-11-07 CISA SSVC decision points changed
- 2026-11-07 Priority changed: LOW → MEDIUM
References
Other 4
- https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-cw2g-2vwq-88w6
- https://github.com/isomorphic-git/isomorphic-git/pull/2370
- https://github.com/isomorphic-git/isomorphic-git/commit/823843d1cd19182df79bc907c767f5bcecb39a0b
- https://github.com/isomorphic-git/isomorphic-git/releases/tag/v1.38.6
More isomorphic-git vulnerabilities
- TI-2026-84487 Path traversal in isomorphic-git checkout lets attackers write files CVSS 3.1HIGH 8.8
- TI-2026-84491 Unbounded memory allocation in isomorphic-git delta handling CVSS 3.1MEDIUM 4.3
- TI-2026-84490 Circular symbolic refs hang ref resolution in isomorphic-git CVSS 3.1MEDIUM 4.3
- TI-2021-06178 Server-side request forgery (SSRF) in @isomorphic-git/cors-proxy CVSS 3.1HIGH 8.6
- TI-2026-60327 isomorphic-git < 1.42.0 Prototype Pollution via getRemoteInfo CVSS 4.0HIGH 7.1
- TI-2021-10885 isomorphic-git before 1.8.2 allows Directory Traversal via a crafted repository. CVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-63478 · CVE Program
- CVE-2026-63478 · NVD
- FIRST EPSS
- CVE-2026-63478 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences