UpHeron
All vulnerabilities

Servers and applications

CVE-2021-27279

Nested Email MyCode Persistent XSS

Severity
Medium 5.4
Published
22 Feb 2021
Last changed
17 Jun 2026
Added to UpHeron
1 Nov 2026
Fixed in
1.8.25
Also known as
GHSA-6483-hcpp-p75w
Sources
NVD, Project advisories (GitHub)

Description

MyBB before 1.8.25 allows stored XSS via nested [email] tags with MyCode (aka BBCode).

Affected software

SoftwareAffected versions
MyBBServers and applications · cpe:a:mybb:mybb
  • Every version before 1.8.25
MyBBServers and applications · github:mybb/mybb
  • Every version before 1.8.25

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2021-27279
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2021-27279
  • GitHub Advisory Database https://github.com/advisories/GHSA-6483-hcpp-p75w
  • github.com https://github.com/mybb/mybb/security/advisories/GHSA-6483-hcpp-p75w