CVE-2015-8976
Cross-site scripting (XSS) vulnerability in MyBB (aka MyBulletinBoard) before 1.6.18 and 1.8.x before 1.8.6 and MyBB Merge System before 1.8.6 might allow remote attackers to inject arbitrary web script or HTML via vectors related to "old upgrade files."
Does this matter?
Lower severity and a low EPSS score (1.04%). Track it; it rarely justifies an emergency change on its own.
Description
Cross-site scripting (XSS) vulnerability in MyBB (aka MyBulletinBoard) before 1.6.18 and 1.8.x before 1.8.6 and MyBB Merge System before 1.8.6 might allow remote attackers to inject arbitrary web script or HTML via vectors related to "old upgrade files."
- CVSS 3.0
- 6.1 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.04% probability · 64th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- mybb/merge system · mybb/mybb
- Source
- cve@mitre.org
EPSS 1.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.openwall.com/lists/oss-security/2016/11/10/8Third Party Advisory
- http://www.openwall.com/lists/oss-security/2016/11/18/1Mailing List, Third Party Advisory
- http://www.securityfocus.com/bid/94397
- https://blog.mybb.com/2015/09/07/mybb-1-8-6-1-6-18-merge-system-1-8-6-release/Release Notes, Vendor Advisory
- http://www.openwall.com/lists/oss-security/2016/11/10/8Third Party Advisory
- http://www.openwall.com/lists/oss-security/2016/11/18/1Mailing List, Third Party Advisory
- http://www.securityfocus.com/bid/94397
- https://blog.mybb.com/2015/09/07/mybb-1-8-6-1-6-18-merge-system-1-8-6-release/Release Notes, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.