CVE-2026-33051: Craftcms/cms Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-3x4w-mxpf-fhqq
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CWE-79
Published
Advisory Summary

CVE-2026-33051 is a MODERATE cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Craftcms/cms libraries in the Packagist ecosystem. The issue involves craft cms vulnerable to stored xss in revision context menu. Remediation is available by upgrading affected packages to version 5.9.11.

CVE-2026-33051 at a Glance

CVE Identifier CVE-2026-33051
GHSA Identifier GHSA-3x4w-mxpf-fhqq
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Craftcms/cms
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2026-33051

To remediate this vulnerability, upgrade all affected Craftcms/cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

craftcms/cms fixed: 5.9.11 
Upgrade craftcms/cms to 5.9.11
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for craftcms/cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-33051, inspect your project dependencies for Craftcms/cms:

inspect dependencies for craftcms/cms

Analyze the terminal output to locate any version of Craftcms/cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.9.11), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Craftcms/cms, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The revision/draft context menu in the element editor renders the creator’s `fullName` as raw HTML due to the use of `Template::raw()` combined with `Craft::t()` string interpolation. A low-privileged control panel user (e.g., Author) can set their fullName to an XSS payload via the profile editor, then create an entry with two saves. If an administrator is logged in and executes a specifically crafted payload while an elevated session is active, the attacker’s account can be elevated to administrator. Users should update to Craft 5.9.11 with the patch to mitigate the issue.

CVE-2026-33051 Affected Craftcms/cms Versions

1 component(s)
Fixed Versions:
5.9.11
Product / Package Ecosystem Affected Versions Fixed Version
craftcms/cms
 Packagist
≥ 5.9.0-beta.1
< 5.9.11
5.9.11

References

GitHub Advisory / Wiki ADVISORY
https://github.com/craftcms/cms/security/advisories/GHSA-3x4w-mxpf-fhqq
NVD — CVE-2026-33051 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33051
Security Fix Commit FIX COMMIT
https://github.com/craftcms/cms/commit/f634a9d21edcafd83a6716047d275f985aba6be1
Craftcms/cms Source Repository REPOSITORY
https://github.com/craftcms/cms
Craftcms/cms Release RELEASE
https://github.com/craftcms/cms/releases/tag/5.9.11

Frequently Asked Questions

What is CVE-2026-33051?
CVE-2026-33051 is a security vulnerability in Craftcms/cms involving Craft CMS Vulnerable to Stored XSS in Revision Context Menu under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Craftcms/cms versions are affected?
Affected versions include releases prior to 5.9.11 across affected packages: craftcms/cms.
What version fixes CVE-2026-33051?
Upgrading to 5.9.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is craftcms/cms affected?
Yes, craftcms/cms is affected in releases prior to 5.9.11. Upgrade your dependency to 5.9.11 or later.
What CWE is associated with CVE-2026-33051?
CVE-2026-33051 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Packagist dependencies for CVE-2026-33051?
Run the dependency tree command: 'inspect dependencies for craftcms/cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-3x4w-mxpf-fhqq",
  "modified" : "2026-03-20T21:23:07Z",
  "published" : "2026-03-18T12:58:23Z",
  "aliases" : [ "CVE-2026-33051" ],
  "summary" : "Craft CMS Vulnerable to Stored XSS in Revision Context Menu",
  "details" : "The revision/draft context menu in the element editor renders the creator’s `fullName` as raw HTML due to the \nuse of `Template::raw()` combined with `Craft::t()` string interpolation. A low-privileged control panel user\n(e.g., Author) can set their fullName to an XSS payload via the profile editor, then create an entry with two\nsaves.\n\nIf an administrator is logged in and executes a specifically crafted payload while an elevated session is active, the attacker’s account can be elevated to administrator.\n\nUsers should update to Craft 5.9.11 with the patch to mitigate the issue.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.9.0-beta.1"
      }, {
        "fixed" : "5.9.11"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.9.10"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/security/advisories/GHSA-3x4w-mxpf-fhqq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33051"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/commit/f634a9d21edcafd83a6716047d275f985aba6be1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/craftcms/cms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/releases/tag/5.9.11"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-18T12:58:23Z",
    "nvd_published_at" : "2026-03-20T06:16:12Z"
  }
}