CVE-2026-62854highCWE-79

CVE-2026-62854: high-severity vulnerability in freescout-help-desk freescout

FreeScout: Stored XSS in mailbox signature via same-origin JS upload

Published

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18Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.6
FreeScout is a self-hosted help desk and shared mailbox. Prior to 1.8.225, a user who can edit a mailbox signature can combine a scriptable file uploaded through /uploads/upload with nested tag fragments that bypass Helper::stripDangerousTags(). The resulting external script is served from the same origin, so the script-src 'self' policy permits it when another user opens the affected mailbox reply editor or new-ticket page. The script executes with the victim's FreeScout privileges and can read visible data and perform same-origin actions. This issue is fixed in version 1.8.225.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
Affected products
freescout-help-desk · freescout
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