CVE-2015-8973
xmlhttp.php in MyBB (aka MyBulletinBoard) before 1.6.18 and 1.8.x before 1.8.6 and MyBB Merge System before 1.8.6 allows remote attackers to bypass intended access restrictions via vectors related to the forum password.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.63%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
xmlhttp.php in MyBB (aka MyBulletinBoard) before 1.6.18 and 1.8.x before 1.8.6 and MyBB Merge System before 1.8.6 allows remote attackers to bypass intended access restrictions via vectors related to the forum password.
- CVSS 3.0
- 8.3 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L
- EPSS
- 1.63% probability · 76th 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 1.6% 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/94397Third Party Advisory, VDB Entry
- 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/94397Third Party Advisory, VDB Entry
- 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.