GitLab Patches XSS and API Denial-of-Service Vulnerabilities in CE/EE
GitLab released security updates for GitLab Community Edition (CE) and Enterprise Edition (EE), shipping patched versions 18.9.2, 18.8.6, and 18.7.6 to address multiple vulnerabilities affecting self-managed deployments. The Canadian Centre for Cyber Security issued advisory AV26-222 urging organizations to review GitLab’s upstream advisory and apply the updates for any instances running versions prior to those releases.
The update fixes 15 security issues, including a high-severity XSS vulnerability (CVE-2026-1090, CVSS 8.7) in Markdown placeholder processing when the relevant feature flag is enabled, which could allow an authenticated attacker to inject malicious JavaScript into a victim’s browser. GitLab also addressed several denial-of-service conditions, including issues impacting the GraphQL API (resource exhaustion via recursion), repository archive endpoints, and JSON payload validation in the protected branches API; additional fixes include webhook-related DoS risks (e.g., CVE-2025-13690, CVE-2025-12576) and a CRLF sequence handling issue (CVE-2026-3848).
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2 events from the most recent confirmed update back to the earliest known activity.
Details disclosed on XSS and API DoS flaws fixed in the GitLab update
Public reporting identified the most critical issue as CVE-2026-1090, an authenticated XSS in Markdown placeholder processing, along with multiple high-severity API-related denial-of-service flaws. The reports also noted GitLab.com and GitLab Dedicated were already patched and that detailed vulnerability reports would be published 30 days after release.
GitLab publishes security advisory and patched CE/EE releases
On 2026-03-11, GitLab published a security advisory for GitLab Community Edition and Enterprise Edition covering 15 vulnerabilities. It released patched versions 18.9.2, 18.8.6, and 18.7.6 for affected versions prior to those releases.
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Warning: Multiple High severity vulnerabilities in GitLab, Patch Immediately! | CCB Safeonweb
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Open sourceGitLab Security Update - Patch for XSS and API DoS Vulnerabilities
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Open sourceGitLab security advisory (AV26-222) - Canadian Centre for Cyber Security
cyber.gc.ca
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GitLab Security Update Fixes Web IDE Token Theft and DoS Vulnerabilities
GitLab released security updates for *Community Edition (CE)* and *Enterprise Edition (EE)*, shipping patched versions **18.8.4**, **18.7.4**, and **18.6.6** for self-managed deployments (with GitLab.com already remediated). The most severe issue, **CVE-2025-7659** (CVSS **8.0**), was attributed to *incomplete validation* in the **Web IDE** that could allow an **unauthenticated** attacker to steal access tokens and use them to access **private repositories**. The same release also addressed multiple high-severity availability and client-side issues, including **CVE-2025-8099** (CVSS **7.5**) enabling **DoS** via repeated/complex **GraphQL** queries and **CVE-2026-0958** (CVSS **7.5**) enabling resource exhaustion by bypassing **JSON validation middleware** limits. Additional fixes included CPU-exhaustion vectors involving specially crafted **Markdown** processing (e.g., **CVE-2026-1456** and **CVE-2026-1458**) and an **XSS** issue in code flow functionality (**CVE-2025-14560**, CVSS **7.3**) that could enable malicious script execution in a victim’s browser session.
Mar 21, 2026
GitLab Patches XSS and Unauthenticated DoS Flaws in Self-Managed CE and EE
GitLab issued emergency security updates for self-managed Community Edition and Enterprise Edition instances to fix multiple high-severity vulnerabilities, including several cross-site scripting (**XSS**) flaws and unauthenticated denial-of-service (**DoS**) issues. The XSS bugs could allow attackers to run malicious JavaScript in users’ browsers, potentially leading to session hijacking, token theft, and repository manipulation, while the DoS flaws could disrupt CI/CD pipelines and broader workflow operations. The affected products are GitLab CE and EE versions earlier than `18.11.3`, `18.10.6`, and `18.9.7`, and administrators were urged to review GitLab’s release guidance and upgrade immediately to those patched versions. GitLab said its cloud-hosted platforms had already been remediated, while self-hosted operators were warned that single-node upgrades require downtime because of database migrations, whereas multi-node deployments can follow standard zero-downtime upgrade procedures.
May 14, 2026
GitLab patches 11 flaws including account takeover and XSS in CE and EE
GitLab released **19.0.2**, **18.11.5**, and **18.10.8** for self-managed Community Edition and Enterprise Edition deployments to fix **11 security vulnerabilities** and additional bugs, and urged administrators to upgrade immediately. The advisory says all versions before those releases are affected, while **GitLab.com** has already been patched and **GitLab Dedicated** customers do not need to take action. GitLab also warned that the update includes database migrations that may cause downtime on single-node instances, though multi-node environments can use zero-downtime upgrade procedures. The most severe issue, **`CVE-2026-6552`** (**CVSS 8.7**), is an improper authorization flaw in GitLab EE's Group SAML identity management that could let an authenticated **group Owner** take over another group member's account under certain conditions. GitLab also fixed **`CVE-2026-10087`**, an Analytics Dashboard cross-site scripting flaw in GitLab EE that could allow an authenticated **developer** to execute arbitrary client-side code in a victim's browser. The broader patch set addresses additional risks including denial of service in Grape API JSON parsing, SSRF, unauthorized access to confidential data, and other authorization bypasses, and government and vendor advisories have called on organizations to apply the patched versions.
Jun 11, 2026