CVE-2026-121730
emailflare before commit cf31f33 Missing Authorization via Inbox Compose Endpoint
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.
INFO
Published Date :
Nov. 3, 2026, 11:17 p.m.
Last Modified :
Nov. 3, 2026, 11:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-121730
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Validate sender address against authorized addresses.
- Implement sender authorization checks.
- Update the API to enforce sender policies.
- Review all email sending functionalities.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-121730.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-121730 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-121730
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-121730 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-121730 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Nov. 03, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-862 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/121xxx/CVE-2026-121730.json">CVE-2026-121730</a> Added Reference https://github.com/0xdps/emailflare Added Reference https://github.com/0xdps/emailflare/blob/d448ea205937a5e82683f89013d4c23159da5b7d/services/inbox-worker/src/routes/inbox/compose.ts Added Reference https://github.com/0xdps/emailflare/commit/cf31f33bbb4a324d5353b8a5db0312fedc19618f Added Reference https://www.vulncheck.com/advisories/emailflare-before-commit-cf31f33-missing-authorization-via-inbox-compose-endpoint