CVE-2026-40591FreeScout: Improper Authorization in Phone Conversation Creation Enables Cross-Mailbox Hidden Customer Modification
- 7.1HighCVSS base score
- 0.21%Exploitation in 30 daysEPSS · top 89% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.214, the phone-conversation creation flow accepts attacker-controlled `customer_id`, `name`, `to_email`, and `phone` values and resolves the target customer in the backend without enforcing mailbox-scoped customer visibility. As a result, a low-privileged agent who can create a phone conversation in Mailbox A can bind the new Mailbox A phone conversation to a hidden customer from Mailbox B and add a new alias email to that hidden customer record by supplying `to_email`. Version 1.8.214 fixes the vulnerability.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
Timeline
ID reserved
By GitHub_M
- 7 days later
· 7 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N |
| NVDNVD · Deferred | 3.1 | High7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.21% · top 89% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Affected products
freescout-help-desk · freescout
- affected < 1.8.214
References
References3
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-9ff4-mmhv-x6jp (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/freescout-help-desk/freescout/commit/83eea1ca47d97c6cdc90c501734bc2579b014a34 (opens in a new tab)x_refsource_MISC
- https://github.com/freescout-help-desk/freescout/releases/tag/1.8.214 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-24187 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-40591)Record last updated .