Cyber Resilience

CVE-2025-9222

XSS in Gitlab 18.2.2 – 18.5.5

XSS
Published
09 January 2026
Modified
15 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
EPSS Score 0.0038 31th percentile
Risk Priority 60 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2025-9222 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Gitlab Gitlab. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-9222 is a stored cross-site scripting vulnerability (CWE-79) in GitLab Community Edition (CE) and Enterprise Edition (EE). It affects all versions from 18.2.2 prior to 18.5.5, 18.6 prior to 18.6.3, and 18.7 prior to 18.7.1. The flaw stems from inadequate sanitization in GitLab Flavored Markdown, enabling injection of malicious scripts. The vulnerability carries a CVSS v3.1 base score of 8.7 (AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N), indicating high severity due to network accessibility, low attack complexity, and potential for cross-origin impacts.

An authenticated user with low privileges (PR:L) can exploit this over the network (AV:N) by submitting specially crafted GitLab Flavored Markdown containing XSS payloads. The attack requires user interaction (UI:R) from victims viewing the stored content, such as in issues, merge requests, or wikis. Successful exploitation executes scripts in the victim's browser context with changed scope (S:C), potentially compromising high confidentiality (C:H) and integrity (I:H) by stealing session data, performing actions on behalf of users, or escalating access within the GitLab instance.

GitLab has remediated the issue through patches, including the release of version 18.7.1. Organizations should upgrade to GitLab 18.5.5, 18.6.3, 18.7.1, or later to mitigate the vulnerability. Further details on the fix are documented in GitLab's patch release notes, the associated issue tracker entry, and the HackerOne disclosure report.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.2.2 before 18.5.5, 18.6 before 18.6.3, and 18.7 before 18.7.1 that could have allowed an authenticated user to achieve stored cross-site scripting by exploiting GitLab Flavored Markdown.

CWE(s)
CWE-79

Related Threats

MITRE ATT&CK Enterprise Techniques

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
attack.mitre.org →
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
attack.mitre.org →
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-0050Same product: Gitlab Gitlab
CVE-2023-2164Same product: Gitlab Gitlab
CVE-2020-13340Same product: Gitlab Gitlab
CVE-2023-6033Same product: Gitlab Gitlab
CVE-2021-22242Same product: Gitlab Gitlab
CVE-2021-39906Same product: Gitlab Gitlab
CVE-2022-1175Same product: Gitlab Gitlab
CVE-2022-1190Same product: Gitlab Gitlab
CVE-2023-2015Same product: Gitlab Gitlab
CVE-2023-2442Same product: Gitlab Gitlab

Affected Assets

gitlab
gitlab
18.7.0 · 18.2.2 — 18.5.5 · 18.2.2 — 18.5.5 · 18.6.0 — 18.6.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.

SI-10 Information Input Validation good match

Input validation directly enforces neutralization of untrusted data before it reaches web output generation.

SI-15 Information Output Filtering good match

Output filtering can catch or sanitize unneutralized script content before it is served to users.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
prevents

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.

A.5.6 Contact with special interest groups partial match
prevents

Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.

A.5.7 Threat intelligence partial match
prevents

Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.

A.8.25 Secure development life cycle partial match
prevents

Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.

A.8.28 Secure coding partial match
prevents

Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.

References