CVE-2026-30913
flarum/nickname: Display name injection in notification emails (autolink & markdown)
Description
Flarum is open-source forum software. When the flarum/nicknames extension is enabled, a registered user can set their nickname to a string that email clients interpret as a hyperlink. The nickname is inserted verbatim into plain-text notification emails, and recipients may be misled into visiting attacker-controlled domains.
INFO
Published Date :
March 10, 2026, 5:40 p.m.
Last Modified :
March 11, 2026, 1:53 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the flarum/nicknames extension.
- Sanitize user-provided nicknames before email insertion.
- Disable the extension if updates are unavailable.
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-2026-30913.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-30913 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-2026-30913
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-2026-30913 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-30913 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.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 10, 2026
Action Type Old Value New Value Added Reference https://github.com/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25 -
New CVE Received by [email protected]
Mar. 10, 2026
Action Type Old Value New Value Added Description Flarum is open-source forum software. When the flarum/nicknames extension is enabled, a registered user can set their nickname to a string that email clients interpret as a hyperlink. The nickname is inserted verbatim into plain-text notification emails, and recipients may be misled into visiting attacker-controlled domains. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://github.com/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25 Added Reference https://github.com/flarum/nicknames/commit/4dde99729abdce8f6e2a7437c86e38735fdcca28 Added Reference https://github.com/flarum/nicknames/releases/tag/v1.8.