CVE-2021-41866
MEDIUMCVSS 5.4/10EPSS 0.48%
Last modified
CVE-2021-41866 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. MyBB before 1.8.28 allows stored XSS because the displayed Template Name value in the Admin CP's theme management is not escaped properly.. EPSS estimates a 0.48% chance of exploitation in the next 30 days.
Description
MyBB before 1.8.28 allows stored XSS because the displayed Template Name value in the Admin CP's theme management is not escaped properly.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mybb | Mybb | < 1.8.28 |
References
- https://github.com/mybb/mybb/security/advisories/Third Party Advisory
- https://github.com/mybb/mybb/security/advisories/GHSA-gxhv-r3m5-6qv7Patch, Third Party Advisory
- https://github.com/mybb/mybb/security/advisories/Third Party Advisory
- https://github.com/mybb/mybb/security/advisories/GHSA-gxhv-r3m5-6qv7Patch, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2021-41866?
MyBB before 1.8.28 allows stored XSS because the displayed Template Name value in the Admin CP's theme management is not escaped properly.
How severe is CVE-2021-41866?
CVE-2021-41866 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.48% probability of exploitation in the next 30 days.
How do I fix CVE-2021-41866?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2021-41866?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
