CVE-2026-40568
FreeScout is a free self-hosted help desk and shared mailbox.
Published Apr 21, 2026 · corrected/updated Jun 17, 2026 · evidence confidence medium
FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a stored cross-site scripting (XSS) vulnerability in the mailbox signature feature. The sanitization function ( ) uses an incomplete blocklist of only four HTML tags ( , , , ) and does not remove event handler attributes. When a mailbox signature is saved via ( ), HTML elements such as , , and with event handler attributes like and pass through sanitization unchanged and are stored in the database. The signature is then rendered as raw HTML via the Blade tag in and re-inserted into the visible DOM by jQuery at , triggering the injected event handlers. Any authenticated user with the ( ) permission on a mailbox -- a delegatable, non-admin permission -- can inject arbitrary HTML and JavaScript into the mailbox signature. The payload fires automatically, with no victim interaction, whenever any agent or administrator opens any conversation in the affected mailbox. This enables session hijacking (under CSP bypass conditions such as IE11 or module-weakened CSP), phishing overlays that work in all browsers regardless of CSP, and chaining to admin-level actions including email exfiltration via mass assignment and self-propagating worm behavior across all mailboxes. Version 1.8.213 fixes the issue.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-40568 is a high public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected version ranges have not been ingested yet. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 8.5. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-116, CWE-79. Sources contributing to this record: cve_org, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Apr 21, 2026 · NIST NVD
Detected
FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a stored cross-site scripting (XSS) vulnerability in the mailbox signature feature. The sanitization function ( ) uses an incomplete blocklist of only four HTML tags ( , , , ) and does not remove event handler attributes. When a mailbox signature is saved via ( ), HTML elements such as , , and with event h
Jun 17, 2026 · NIST NVD
Updated
FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a stored cross-site scripting (XSS) vulnerability in the mailbox signature feature. The sanitization function ( ) uses an incomplete blocklist of only four HTML tags ( , , , ) and does not remove event handler attributes. When a mailbox signature is saved via ( ), HTML elements such as , , and with event h
Sources
- CVE.orgVulnerability recordCVE-2026-40568
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-40568
FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a stored cross-site scripting (XSS) vulnerability in the mailbox signature feature. The sanitization function ( ) uses an incomplete
nvd.nist.gov