Auth bypass in 0xdps Emailflare
CVE-2026-121730
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.
Vulnerability class: Broken Access Control
Published .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/0xdps/emailflare/commit/cf31f33bbb4a324d5353b8a5db0312fedc19618f (patch)
- github.com/0xdps/emailflare (product)
- github.com/0xdps/emailflare/blob/d448ea205937a5e82683f89013d4c23159da5b7d/servi… (technical-description)
- www.vulncheck.com/advisories/emailflare-before-commit-cf31f33-missing-authoriza… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-121730?
- CVE-2026-121730 is a medium-severity vulnerability in 0xdps Emailflare, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-11-03.
- How severe is CVE-2026-121730?
- Medium severity. CVSS v3 base score is 6.5 out of 10.