CVE-2026-109351 GitoxideLabs CVE debrief

Who should care

Defenders who are responsible for securing Git-based systems and services should be aware of this vulnerability and take steps to mitigate it. This includes reviewing the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. They should also plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Why it matters

This vulnerability has a high CVSS score and could potentially be used to launch denial-of-service attacks against Git-based systems. Defenders should prioritize patching or mitigating this vulnerability to prevent potential service disruptions.

• Potential denial-of-service attacks against Git-based systems
• Increased risk of service disruption or outage
• Need for patching or mitigation to prevent exploitation

Technical summary

The vulnerability exists in the gix-pack library, which is used for packing and unpacking Git objects. An attacker can exploit this vulnerability by serving a malicious pack header with a large object count, which can cause the process to crash. The vulnerability is caused by an uncontrolled memory allocation issue in the gix-pack library. This issue allows remote attackers to abort the process by supplying a huge pack-header object count. Malicious remotes can serve a 12-byte pack header claiming 0xFFFFFFFF objects, forcing Tree::with_capacity to reserve hundreds of gigabytes and crash clone or fetch operations.

Defensive priority

Defenders should prioritize patching or mitigating this vulnerability to prevent potential denial-of-service attacks.

Recommended defensive actions

• Patch gix-pack to version 0.75.0 or later
• Restrict access to the gix-pack service to trusted sources
• Monitor gix-pack logs for potential denial-of-service attacks
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is caused by an uncontrolled memory allocation issue in the gix-pack library. An attacker can exploit this vulnerability by serving a malicious pack header with a large object count, which can cause the process to crash.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.