No VulnCrest analysis published for this CVE yet. Below is the original CNA/NVD description, unmodified.
Description
isomorphic-git is a pure JavaScript implementation of Git for Node.js and browsers. Prior to 1.38.6, isomorphic-git reads a server-controlled targetSize while applying a packfile delta in src/utils/applyDelta.js and passes it without a bound to Buffer.alloc(targetSize). A malicious or man-in-the-middle-controlled remote can send one delta header that causes git.clone() or git.fetch() to allocate approximately 2 GB before validating the actual delta output. GitPackIndex.fromPack swallows the later size-mismatch error, so a host with sufficient memory may retain the resource waste without a visible failure, while containers, serverless functions, and small virtual machines may terminate. Node.js heap limits do not mitigate the off-heap Buffer allocation. This issue is fixed in version 1.38.6.
Exploits & detection
No public PoC or detection template found yet.
Timeline
- Published: 03 Nov 2026
- Last modified upstream: 07 Nov 2026
Sources & licenses
- CVE / CVSS / CWE
- NVD record ↗ (unmodified). This product uses the NVD API but is not endorsed or certified by the NVD. CVE® © The MITRE Corporation.
- Exploitation
- CISA KEV (CC0) · EPSS by FIRST.org
- References used for the analysis
- https://github.com/isomorphic-git/isomorphic-git/commit/823843d1cd19182df79bc907c767f5bcecb39a0b
- https://github.com/isomorphic-git/isomorphic-git/pull/2370
- https://github.com/isomorphic-git/isomorphic-git/releases/tag/v1.38.6
- https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-9x82-4j54-863h
- https://github.com/isomorphic-git/isomorphic-git/security/advisories/GHSA-9x82-4j54-863h
- Analysis, summary and remediation
- © VulnCrest