CVE-2016-9415
MyBB (aka MyBulletinBoard) before 1.8.8 on Windows and MyBB Merge System before 1.8.8 on Windows allow remote attackers to overwrite arbitrary CSS files via vectors related to "style import."
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.86%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
MyBB (aka MyBulletinBoard) before 1.8.8 on Windows and MyBB Merge System before 1.8.8 on Windows allow remote attackers to overwrite arbitrary CSS files via vectors related to "style import."
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 1.86% probability · 79th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-284
- Affected
- mybb/merge system · mybb/mybb
- Source
- cve@mitre.org
EPSS 1.9% since 27 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/2016/11/10/8Mailing List, Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2016/11/18/1Mailing List, Patch, Third Party Advisory
- http://www.securityfocus.com/bid/94396Third Party Advisory, VDB Entry
- https://blog.mybb.com/2016/10/17/mybb-1-8-8-merge-system-1-8-8-release/Patch, Release Notes, Vendor Advisory
- http://www.openwall.com/lists/oss-security/2016/11/10/8Mailing List, Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2016/11/18/1Mailing List, Patch, Third Party Advisory
- http://www.securityfocus.com/bid/94396Third Party Advisory, VDB Entry
- https://blog.mybb.com/2016/10/17/mybb-1-8-8-merge-system-1-8-8-release/Patch, 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.