CVE-2026-62854
FreeScout: Stored XSS in mailbox signature via same-origin JS upload
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.
Fixes and workarounds
Fix
FreeScout: GitHub reports patched versions 1.8.226. Check the advisory for the affected release branch.
Source: GitHub GHSA-jpq8-j69f-mj98Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| freescout freescout-help-desk |
< 1.8.225 (affected) | CNA: GitHub_M |
FreeScoutFreeScout
|
<1.8.226 (affected, GitHub advisory range) | GitHub GHSA-jpq8-j69f-mj98 |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 7.6 high |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N | CNA: GitHub_M |
| 3.1 / 7.6 high |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N | NVD: [email protected] |
Exploit evidence
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-jpq8-j69f-mj98
exploit · ADP: CISA-ADP
References
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-jpq8-j69f-mj98CNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/freescout-help-desk/freescout/commit/315ad05f73886649cb8bc2c014dd74b62cc28502CNA: GitHub_M · x_refsource_MISC
- https://github.com/freescout-help-desk/freescout/commit/7f6a5042c1326ceaf511f13982178dce036cedbeCNA: GitHub_M · x_refsource_MISC
- https://github.com/freescout-help-desk/freescout/releases/tag/1.8.225CNA: GitHub_M · x_refsource_MISC
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-jpq8-j69f-mj98ADP: CISA-ADP · exploit
- https://github.com/freescout-help-desk/freescout/commit/315ad05f73886649cb8bc2c014dd74b62cc28502[email protected]
- https://github.com/freescout-help-desk/freescout/commit/7f6a5042c1326ceaf511f13982178dce036cedbe[email protected]
- https://github.com/freescout-help-desk/freescout/releases/tag/1.8.225[email protected]
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-jpq8-j69f-mj98[email protected]
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-jpq8-j69f-mj98GitHub Security Advisories · advisory
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