CVE-2026-121551
PostfixAdmin through 4.0.5 Stored XSS via TOTP Exception Description
Description
PostfixAdmin through 4.0.5 contains a stored cross-site scripting vulnerability that allows authenticated mailbox users to inject script by creating a TOTP exception with an unescaped description. When a global administrator views totp-exceptions.php, the script runs in the admin session and can issue authenticated admin requests using the page's CSRF token.
INFO
Published Date :
Nov. 3, 2026, 4:17 p.m.
Last Modified :
Nov. 3, 2026, 7:18 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update PostfixAdmin to a version later than 4.0.5.
- Sanitize user-supplied input for TOTP exception descriptions.
- Ensure proper output encoding when displaying exception descriptions.
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-2026-121551.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-121551 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-2026-121551
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-2026-121551 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-121551 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.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Nov. 03, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-121551', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-11-03T17:21:11.734226Z'} -
New CVE Received by [email protected]
Nov. 03, 2026
Action Type Old Value New Value Added Description PostfixAdmin through 4.0.5 contains a stored cross-site scripting vulnerability that allows authenticated mailbox users to inject script by creating a TOTP exception with an unescaped description. When a global administrator views totp-exceptions.php, the script runs in the admin session and can issue authenticated admin requests using the page's CSRF token. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/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:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/121xxx/CVE-2026-121551.json">CVE-2026-121551</a> Added Reference https://github.com/postfixadmin/postfixadmin Added Reference https://github.com/postfixadmin/postfixadmin/blob/v4.0.5/public/users/totp-exceptions.php#L128 Added Reference https://github.com/postfixadmin/postfixadmin/blob/v4.0.5/templates/totp-exceptions.tpl#L56 Added Reference https://github.com/postfixadmin/postfixadmin/commit/0a894b08769481ce1a7f0f42af901c6d9f88fa9c Added Reference https://github.com/postfixadmin/postfixadmin/issues/1185 Added Reference https://github.com/postfixadmin/postfixadmin/pull/1172 Added Reference https://github.com/postfixadmin/postfixadmin/pull/1186 Added Reference https://www.vulncheck.com/advisories/postfixadmin-through-4.0.5-stored-xss-via-totp-exception-description