CVE-2026-21623: Stackideas.com EasyDiscuss extension for Joomla · Cross-site Scripting
Affects Stackideas.com EasyDiscuss extension for JoomlaSource CVE Database V5
Not known to be exploited · CVSS 9.4 Critical.
Data as of 26 Oct 2026, 07:57 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Stackideas.comEasyDiscuss extension for Joomla | Affected
| Fixed in– |
AI-suggested
To mitigate CVE-2026-21623, European organizations should: 1) Immediately monitor for and apply any official patches or updates released by Stackideas.com for the EasyDiscuss extension. 2) If patches are not yet available, consider temporarily disabling the EasyDiscuss forum functionality or restricting access to trusted users only. 3) Implement robust input validation and output encoding on all user-generated content, particularly in forum posts, to neutralize malicious scripts. 4) Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 5) Conduct regular security audits and penetration testing focused on web application vulnerabilities. 6) Educate users about the risks of interacting with suspicious forum content to reduce the likelihood of successful exploitation. 7) Monitor web server and application logs for unusual activity indicative of attempted XSS attacks. 8) Consider using web application firewalls (WAFs) with rules tailored to detect and block XSS payloads targeting Joomla extensions.
Description
Lack of input filterung leads to a persistent XSS vulnerability in the forum post handling of the Easy Discuss component for Joomla.