CVE-2026-1090Public exploitNetwork attack vector

Stored XSS via unescaped Markdown placeholder hyperlink

Published Mar 11, 2026 · Updated Mar 11, 2026

Stored XSS in GitLab 10.6 before 18.7.6, 18.8 before 18.8.6, and 18.9 before 18.9.2 allows remote authenticated users to run browser script. Banzai's PlaceholdersPostFilter inserts an unescaped quote from a placeholder hyperlink into redacted HTML, allowing crafted tag and snippet content to break the attribute boundary and inject markup. The markdown_placeholders flag must be enabled, and another user must open the attacker's public snippet and click its crafted link; the script then runs in that user's GitLab origin.

CVSS severity8.7
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in GitLab 10.6 before 18.7.6, 18.8 before 18.8.6, and 18.9 before 18.9.2 allows remote authenticated users to run browser script. Banzai's PlaceholdersPostFilter inserts an unescaped quote from a placeholder hyperlink into redacted HTML, allowing crafted tag and snippet content to break the attribute boundary and inject markup. The markdown_placeholders flag must be enabled, and another user must open the attacker's public snippet and click its crafted link; the script then runs in that user's GitLab origin.

The record

CVE
CVE-2026-1090
Published
Mar 11, 2026
Updated
Mar 11, 2026
Vendor
GitLab
Product
GitLab
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.6 <18.7.6
  2. Affected versionversion=18.8 <18.8.6
  3. Affected versionversion=18.9 <18.9.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=10.6 <18.7.6; version=18.8 <18.8.6; version=18.9 <18.9.2

Published CVSS scores

8.7GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo