emailflare before commit cf31f33 Missing Authorization via Inbox Compose Endpoint

Advisories

emailflare before commit cf31f33 Missing Authorization via Inbox Compose Endpoint

Severity: high
Date: 11/3/2026
Affecting: emailflare >= 0, < cf31f33bbb4a324d5353b8a5db0312fedc19618f
CVE: CVE-2026-121730
CWE: CWE-862 Missing Authorization
CVSS: 7.1
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References: Patch Commit
https://github.com/0xdps/emailflare
https://github.com/0xdps/emailflare/blob/d448ea205937a5e82683f89013d4c23159da5b7d/services/inbox-worker/src/routes/inbox/compose.ts
Credit: Mansurzhan Mavlankulov, Devendra Pratap
Description: emailflare before commit cf31f33 contains a missing authorization vulnerability in POST /api/inbox/compose that allows authenticated members to send mail as any sender address. Attackers can supply an arbitrary from field, which is passed unchecked to the Cloudflare send call, to impersonate other users or the organization to external recipients.

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