# CVE-2026-3988 — GitLab

> As of 2026-03-25, CVE-2026-3988 is a HIGH-severity vulnerability in GitLab, CVSS v3.1 7.5, EPSS 0.8% (57.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-3988, most recently “Critical GitLab GraphQL Flaw (CVE-2026-19478, CVSS 9.4) Could Let Unauthenticated Attackers Delete Public Projects”.

**Last updated:** 2026-03-25

## What is CVE-2026-3988?

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.5 before 18.8.7, 18.9 before 18.9.3, and 18.10 before 18.10.1 that could have allowed an unauthenticated user to cause a denial of service by making the GitLab instance unresponsive due to improper input validation in GraphQL request processing.

The record classifies CVE-2026-3988 under weakness class [CWE-407](https://cwe.mitre.org/data/definitions/407.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 212 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.8% probability of exploitation in the next 30 days, higher than 57.0% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-03-25

## Is CVE-2026-3988 being exploited?

It currently carries a trending score of 19 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [GitLab](https://intel.threadlinqs.com/vendors/gitlab): GitLab

## How to fix CVE-2026-3988

No vendor patch reference has been recorded for CVE-2026-3988 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-3988

1 tracked threat in the Threadlinqs corpus references CVE-2026-3988, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Critical GitLab GraphQL Flaw (CVE-2026-19478, CVSS 9.4) Could Let Unauthenticated Attackers Delete Public Projects](https://intel.threadlinqs.com/threat/TL-2026-2048) — CRITICAL · 2026-08-17

## Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on 2026-10-10.

**Exploit and proof of concept**

- [hackerone.com — technical description](https://hackerone.com/reports/3597342)

**Other references**

- [gitlab.com](https://gitlab.com/gitlab-org/gitlab/-/work_items/593140)
- [about.gitlab.com](https://about.gitlab.com/releases/2026/03/25/patch-release-gitlab-18-10-1-released/)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-3988
Full detection coverage and IOCs for threats exploiting CVE-2026-3988 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp