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.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-639"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40591.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.8.214"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "83eea1ca47d97c6cdc90c501734bc2579b014a34"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "1.8.214",
"range": [
{
"fixed": "abf82ecc3ea85d53b319d27d3109560ff74d1173"
}
],
"source": "REFERENCES_TAG"
}
]
}