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PatchSiren cyber security CVE debrief

CVE-2016-9416 Mybb CVE debrief

CVE-2016-9416 is a critical SQL injection vulnerability in MyBB’s users data handler. According to the CVE record, affected MyBB and MyBB Merge System installations before 1.8.8 can be abused by a remote attacker to execute arbitrary SQL commands.

Vendor
Mybb
Product
Merge System
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2017-01-31
Original CVE updated
2026-05-13
Advisory published
2017-01-31
Advisory updated
2026-05-13

Who should care

Administrators and operators running MyBB or MyBB Merge System, especially any deployment on version 1.8.7 or earlier, should treat this as high priority. Public-facing forum installations deserve the fastest attention.

Technical summary

The NVD record classifies this issue as CWE-89 (SQL Injection) with CVSS 3.0 vector AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating a network-reachable issue that requires no privileges or user interaction and can have severe confidentiality, integrity, and availability impact. The supplied affected CPE criteria list MyBB and MyBB Merge System through version 1.8.7. The CVE description states the flaw is in the users data handler and allows remote attackers to execute arbitrary SQL via unspecified vectors. The supplied MyBB release-note reference identifies 1.8.8 / Merge System 1.8.8 as the fixing release.

Defensive priority

Immediate. Because this is remotely reachable, unauthenticated, and rated critical, patching to 1.8.8 or later should be prioritized ahead of routine maintenance. If upgrading is delayed, reduce exposure and monitor for signs of database tampering or unauthorized queries.

Recommended defensive actions

  • Upgrade MyBB and MyBB Merge System to version 1.8.8 or later.
  • Inventory all deployments and confirm whether any instance is on 1.8.7 or earlier.
  • Prioritize internet-facing forum instances for emergency maintenance.
  • Review database and application logs for abnormal SQL activity or unexpected changes.
  • If compromise is suspected, rotate credentials and validate database integrity and backups.
  • Apply temporary access restrictions until patched if immediate upgrade is not possible.

Evidence notes

This debrief is grounded in the supplied NVD CVE record and its cited references. The NVD data lists CVE-2016-9416 as a modified record with CVSS 3.0 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, CWE-89, and vulnerable CPE criteria for mybb:mybb and mybb:merge_system through 1.8.7. The record also cites a MyBB 1.8.8 / Merge System 1.8.8 release note, OSS-security mailing list references, and a SecurityFocus BID entry as supporting references.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-9416 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-9416

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-9416 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-9416

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.