CVE-2026-54717: Silverstripe Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-w3cp-g2pf-65wh
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CVSS 5.4
CWE-79
Published
Advisory Summary

CVE-2026-54717 is a MODERATE (CVSS 5.4) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Silverstripe libraries in the Packagist ecosystem. The issue involves xss in breadcrumbs in page list view. Remediation is available by upgrading affected packages to version 6.2.1.

CVE-2026-54717 at a Glance

CVE Identifier CVE-2026-54717
GHSA Identifier GHSA-w3cp-g2pf-65wh
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Silverstripe
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 5.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-54717

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

silverstripe/cms fixed: 6.2.1 
Upgrade silverstripe/cms to 6.2.1
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 silverstripe/cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-54717, inspect your project dependencies for Silverstripe:

inspect dependencies for silverstripe/cms

Analyze the terminal output to locate any version of Silverstripe in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.2.1), 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 Silverstripe, 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

### Impact Page breadcrumbs in the CMS are vulnerable to XSS when viewed using the page list view ### Reporter Fase Rais Baradika

CVE-2026-54717 Affected Silverstripe Versions

1 component(s)
Fixed Versions:
6.2.1
Product / Package Ecosystem Affected Versions Fixed Version
silverstripe/cms
 Packagist
< 6.2.1
6.2.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/silverstripe/silverstripe-cms/security/advisories/GHSA-w3cp-g2pf-65wh
Silverstripe Source Repository REPOSITORY
https://github.com/silverstripe/silverstripe-cms/pull/3175
Security Fix Commit FIX COMMIT
https://github.com/silverstripe/silverstripe-cms/commit/62f9912baa18c80304f3fa8b6eca71bb5dc2d21e
Silverstripe Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/cms/CVE-2026-54717.yaml
Silverstripe Source Repository REPOSITORY
https://github.com/silverstripe/silverstripe-cms
Silverstripe Release RELEASE
https://github.com/silverstripe/silverstripe-cms/releases/tag/6.2.1
Silverstripe Release RELEASE
https://www.silverstripe.org/download/security-releases/cve-2026-54717

Frequently Asked Questions

What is CVE-2026-54717?
CVE-2026-54717 is a security vulnerability in Silverstripe involving XSS in breadcrumbs in page list view under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Silverstripe versions are affected?
Affected versions include releases prior to 6.2.1 across affected packages: silverstripe/cms.
What version fixes CVE-2026-54717?
Upgrading to 6.2.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is silverstripe/cms affected?
Yes, silverstripe/cms is affected in releases prior to 6.2.1. Upgrade your dependency to 6.2.1 or later.
What is the CVSS score of CVE-2026-54717?
CVE-2026-54717 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2026-54717?
CVE-2026-54717 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-2026-54717?
Run the dependency tree command: 'inspect dependencies for silverstripe/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-w3cp-g2pf-65wh",
  "modified" : "2026-08-06T20:27:22Z",
  "published" : "2026-08-06T20:27:22Z",
  "aliases" : [ "CVE-2026-54717" ],
  "summary" : "Silverstripe: XSS in breadcrumbs in page list view",
  "details" : "### Impact\nPage breadcrumbs in the CMS are vulnerable to XSS when viewed using the page list view\n\n### Reporter\nFase Rais Baradika",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "silverstripe/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.2.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/silverstripe/silverstripe-cms/security/advisories/GHSA-w3cp-g2pf-65wh"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/silverstripe/silverstripe-cms/pull/3175"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/silverstripe/silverstripe-cms/commit/62f9912baa18c80304f3fa8b6eca71bb5dc2d21e"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/cms/CVE-2026-54717.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/silverstripe/silverstripe-cms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/silverstripe/silverstripe-cms/releases/tag/6.2.1"
  }, {
    "type" : "WEB",
    "url" : "https://www.silverstripe.org/download/security-releases/cve-2026-54717"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-06T20:27:22Z",
    "nvd_published_at" : null
  }
}