Vulnerability · CVE-2026-40568
FreeScout is a free self-hosted help desk and shared mailbox.
Published Apr 21, 2026 · catalog updated Jun 17, 2026 · FreeScout is a free
Check if you run it
No confirmed exploitation is on record for CVE-2026-40568. EPSS is 0.41%. Act only if a listed version of FreeScout is a free is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (FreeScout is a free).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High8.5
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.41%
- Remediation
- Advisory link
- Affected products
- See sources for product scope
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.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-40568
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-40568. EPSS is 0.41%. Act only if a listed version of FreeScout is a free is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-116; CWE-79: Cross-site Scripting (XSS). EPSS 0.41%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
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 - FIRST EPSSExploitation probabilityCVE-2026-40568
30-day exploitation probability 0.4%
first.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
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.