Critical GitLab Flaw Enables XSS and Unauthenticated DoS Attacks

GitLab has rushed out emergency security updates after uncovering a dangerous cluster of vulnerabilities that could allow attackers to silently hijack developer sessions or bring entire CI/CD pipelines to a halt.

The flaws, disclosed on May 13, 2026, impact both Community Edition (CE) and Enterprise Edition (EE), prompting urgent warnings for organizations running self-managed instances.

The company released patched versions 18.11.3, 18.10.6, and 18.9.7, addressing 25 vulnerabilities spanning Cross-Site Scripting (XSS), Denial-of-Service (DoS), and access control issues.

While GitLab.com is already protected, unpatched on-premise deployments remain highly exposed to exploitation.

High-Severity XSS Enables Session Hijacking

Among the most critical issues are four high-severity XSS vulnerabilities, each with a CVSS score of 8.7.

These flaws originate from improper input sanitization in widely used components such as analytics dashboards, global search, and Duo Agent output rendering.

Attackers with standard authenticated access can inject malicious JavaScript into these features. Once executed in a victim’s browser, the payload can steal session tokens, impersonate users, and manipulate repositories without detection.

This makes insider threats or compromised developer accounts, particularly dangerous.

Security researchers warn that such attacks could persist unnoticed, enabling long-term espionage within development environments.

For example, a malicious script embedded in a shared dashboard could silently capture credentials from multiple engineers accessing the same project.

Unauthenticated DoS Threatens CI/CD Availability

In addition to XSS flaws, GitLab patched three high-severity DoS vulnerabilities (CVSS 7.5) that require no authentication.

These bugs affect the CI/CD job update API, Duo Workflows API, and internal API endpoints.

By sending specially crafted requests or malformed JSON payloads, attackers can exhaust server resources and crash GitLab services remotely.

This opens the door to large-scale disruption, where threat actors can deliberately halt software delivery pipelines, delaying releases and impacting business operations.

Beyond these, GitLab resolved multiple medium-severity issues, including improper authorization in GraphQL (CVE-2026-1322), CSRF in JiraConnect integrations, and unauthorized access to sensitive package and registry components.

CVE IDType / Short TitleImpacted AreaSeverity
CVE-2026-7481XSS in analytics dashboardGitLab EE AnalyticsHigh
CVE-2026-5297XSS in global searchGitLab CE/EEHigh
CVE-2026-6073XSS in Duo Agent outputGitLab EE Duo AgentHigh
CVE-2026-7377XSS in analytics dashboardGitLab EE AnalyticsHigh
CVE-2026-1659DoS in CI/CD job update APIGitLab CE/EE CI/CDHigh
CVE-2025-14870DoS in Duo Workflows APIGitLab CE/EEHigh
CVE-2025-14869DoS in internal APIGitLab CE/EEHigh
CVE-2026-1322Improper authorization in GraphQLGitLab CE/EE GraphQLMedium
CVE-2026-1184DoS in Insights configurationGitLab EE InsightsMedium
CVE-2026-4524Access control in Issues APIGitLab CE/EEMedium
CVE-2026-8280DoS in CSV parserGitLab CE/EEMedium
CVE-2026-4527CSRF in JiraConnectGitLab CE/EEMedium
CVE-2026-3160Confused Deputy in JiraGitLab CE/EEMedium
CVE-2026-6335XSS in Banzai sanitizerGitLab CE/EEMedium
CVE-2025-12669XSS in email notificationsGitLab CE/EEMedium
CVE-2026-3607Access control in Helm uploadGitLab CE/EEMedium
CVE-2026-3074Improper access in NuGet ServerGitLab CE/EEMedium
CVE-2026-1338Access control in Container RegistryGitLab CE/EEMedium
CVE-2026-8144Missing auth in group user searchGitLab CE/EEMedium
CVE-2026-6063Improper access in code owner rulesGitLab EEMedium
CVE-2026-3073Access control in PyPI rulesGitLab CE/EEMedium
CVE-2025-13874Improper access in issue links APIGitLab CE/EEMedium
CVE-2026-7471SSRF in virtual registry redirectGitLab EELow
CVE-2026-2900Access control in GraphQL mutationsGitLab EELow
CVE-2026-6883Missing auth in Security PolicyGitLab EELow

Organizations using self-managed GitLab deployments are strongly advised to upgrade immediately. Delaying patches could leave development infrastructure vulnerable to stealthy account compromise or disruptive service outages, both of which pose significant operational and security risks.

Follow us on Google News , LinkedIn and X to Get More Instant UpdatesSet Cyberpress as a Preferred Source in Google

The post Critical GitLab Flaw Enables XSS and Unauthenticated DoS Attacks appeared first on Cyber Security News.


Discover more from RSS Feeds Cloud

Subscribe to get the latest posts sent to your email.

Leave a Reply

Your email address will not be published. Required fields are marked *

Discover more from RSS Feeds Cloud

Subscribe now to keep reading and get access to the full archive.

Continue reading