CVE-2026-63476
Description
A flaw was found in isomorphic-git. A malicious or compromised remote Git server can cause a Denial of Service (DoS) by sending a specially crafted packfile delta header with an excessively large target size during clone or fetch operations. Because isomorphic-git allocates memory for the target size without proper bounds checking, this issue leads to excessive memory consumption and can crash applications running in memory-constrained environments, such as containers or serverless functions.
Statement
This vulnerability is rated as having Moderate impact for Red Hat products because exploitation requires connecting to an untrusted or compromised remote repository, limiting the blast radius to process termination via memory exhaustion without impacting data integrity or confidentiality. In containerized environments such as Red Hat Developer Hub and OpenShift Serverless, invoking clone or fetch operations against a hostile Git endpoint can trigger excessive buffer allocations that terminate the affected pod. Environments interacting solely with verified, internal Git servers are not exposed to this issue during normal operations.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.3 | N/A | 4.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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