CVE-2026-55779

Description

Silverstripe Versioned provides versioning for Silverstripe models. Prior to 3.2.1, RestoreAction::getRestoreMessage() in src/RestoreAction.php builds ArchiveAdmin restore notifications rendered as CAST_HTML and inserts $restoredItem->Title, $restoredItem->URLSegment, $restoredItem->CMSEditLink(), and $changedProperty['value'] without applying Convert::raw2xml(). When an administrator restores an archived page containing a crafted title or URL segment, the generated restoration message can execute stored JavaScript in the administrator's browser, compromising the confidentiality and integrity of the CMS session. This issue is fixed in version 3.2.1.

References

• https://github.com/silverstripe/silverstripe-versioned/commit/6e30a2cf8d4b9233690464da61bd0fc4d3e92952
• https://github.com/silverstripe/silverstripe-versioned/pull/541
• https://github.com/silverstripe/silverstripe-versioned/releases/tag/3.2.1
• https://github.com/silverstripe/silverstripe-versioned/security/advisories/GHSA-m4g4-86qc-v8w7
• https://www.silverstripe.org/download/security-releases/cve-2026-55779