CVE-2021-27889

MediumCVSS 6.1/10Last modified Jun 17, 2026

Description

Cross-site Scripting (XSS) vulnerability in MyBB before 1.8.26 via Nested Auto URL when parsing messages.

Metrics

CVSS 3.1 6.1/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Weakness enumeration

CWE-79

Affected software

Vendor	Product	Versions
n/a	n/a	n/a

References

http://packetstormsecurity.com/files/161908/MyBB-1.8.25-Remote-Command-Execution.htmlExploit, Third Party Advisory, VDB Entry
https://blog.sonarsource.com/mybb-remote-code-execution-chainExploit, Third Party Advisory
https://github.com/mybb/mybb/security/advisories/GHSA-xhj7-3349-mqcmPatch, Third Party Advisory
http://packetstormsecurity.com/files/161908/MyBB-1.8.25-Remote-Command-Execution.htmlExploit, Third Party Advisory, VDB Entry
https://blog.sonarsource.com/mybb-remote-code-execution-chainExploit, Third Party Advisory
https://github.com/mybb/mybb/security/advisories/GHSA-xhj7-3349-mqcmPatch, Third Party Advisory

Timeline

Published: Mar 15, 2021
Last modified: Jun 17, 2026
NVD status: Modified

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