CVE-2026-0958 – This vulnerability allows unauthenticated attac... (How to Fix)

Q: What is the severity of CVE-2026-0958?

CVE-2026-0958 has a CVSS score of 7.5 (HIGH). This vulnerability allows unauthenticated attackers to cause denial of service on GitLab instances by bypassing JSON validation middleware limits, leading to memory or CPU exhaustion. It affects all GitLab Community Edition and Enterprise Edition installations running vulnerable versions. The attack requires no authentication and can render GitLab services unavailable.

📋 TL;DR

This vulnerability allows unauthenticated attackers to cause denial of service on GitLab instances by bypassing JSON validation middleware limits, leading to memory or CPU exhaustion. It affects all GitLab Community Edition and Enterprise Edition installations running vulnerable versions. The attack requires no authentication and can render GitLab services unavailable.

💻 Affected Systems

Products:

GitLab Community Edition
GitLab Enterprise Edition

Versions: 18.4 to 18.6.5, 18.7 to 18.7.3, 18.8 to 18.8.3

Operating Systems: All supported platforms

Default Config Vulnerable: ⚠️ Yes

Notes: All deployments including self-managed, cloud-native, and containerized installations are affected if running vulnerable versions.

📦 What is this software?

Gitlab by Gitlab

GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...

Learn more about Gitlab →

Gitlab by Gitlab

GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...

Learn more about Gitlab →

Gitlab by Gitlab

GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...

Learn more about Gitlab →

Gitlab by Gitlab

GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...

Learn more about Gitlab →

Gitlab by Gitlab

GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...

Learn more about Gitlab →

Gitlab by Gitlab

GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...

Learn more about Gitlab →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete service unavailability due to resource exhaustion, potentially affecting all GitLab services including repositories, CI/CD pipelines, and user authentication.

🟠

Likely Case

Partial or intermittent service degradation affecting GitLab performance and availability for users.

🟢

If Mitigated

Minimal impact with proper rate limiting, resource monitoring, and network segmentation in place.

🌐 Internet-Facing: HIGH - Unauthenticated exploitation from internet-facing instances makes this easily accessible to attackers.

🏢 Internal Only: MEDIUM - Internal attackers or compromised internal systems could still exploit this, but requires network access.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

The vulnerability involves bypassing JSON validation limits which is relatively straightforward to exploit once the technique is understood.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 18.6.6, 18.7.4, or 18.8.4

Vendor Advisory: https://about.gitlab.com/releases/2026/02/10/patch-release-gitlab-18-8-4-released/

Restart Required: Yes

Instructions:

1. Backup your GitLab instance. 2. Update to GitLab 18.6.6, 18.7.4, or 18.8.4 depending on your current version. 3. Restart GitLab services. 4. Verify the update was successful.

🔧 Temporary Workarounds

Rate Limiting Configuration

all

Implement strict rate limiting on JSON endpoints to prevent abuse

Configure nginx or load balancer rate limiting for GitLab endpoints

Network Access Control

all

Restrict access to GitLab instance to trusted networks only

Configure firewall rules to limit GitLab access

🧯 If You Can't Patch

Implement Web Application Firewall (WAF) rules to detect and block JSON payload abuse
Monitor system resources closely and implement automated alerts for abnormal CPU/memory usage

🔍 How to Verify

Check if Vulnerable:

Check GitLab version via admin panel or command line. If version is between 18.4-18.6.5, 18.7-18.7.3, or 18.8-18.8.3, the system is vulnerable.

Check Version:

sudo gitlab-rake gitlab:env:info | grep Version

Verify Fix Applied:

Verify GitLab version is 18.6.6, 18.7.4, or 18.8.4 or higher. Test JSON endpoint functionality remains normal.

📡 Detection & Monitoring

Log Indicators:

Abnormally large JSON payloads in logs
Repeated failed JSON validation attempts
High resource usage alerts

Network Indicators:

Unusual traffic patterns to JSON endpoints
Multiple requests with malformed JSON from single sources

SIEM Query:

source="gitlab" AND ("JSON validation" OR "payload too large") AND severity=ERROR

📊 Metadata

CVE ID: CVE-2026-0958

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-436

EPSS Score: 0.03% exploit probability (6.1th percentile)

Published: February 11, 2026

Last Updated: February 13, 2026

🔗 References

https://about.gitlab.com/releases/2026/02/10/patch-release-gitlab-18-8-4-released/ Release Notes,Vendor Advisory
https://gitlab.com/gitlab-org/gitlab/-/issues/586202 Broken Link,Issue Tracking
https://hackerone.com/reports/3463363 Permissions Required

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

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