CVE-2026-46482

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Source
https://cve.org/CVERecord?id=CVE-2026-46482
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46482.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-46482
Aliases
  • GHSA-v2h7-4jp7-j6hh
Published
2026-08-18T15:44:59.644Z
Modified
2026-08-20T03:54:21.915307829Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
Summary
MyBB: Security Question insufficient validation
Details

Impact

The registration component does not validate the text-based Security Question CAPTCHA correctly, allowing attackers to bypass the challenge via a specially crafted value.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Details

The public Registration workflow (member.php?action=do_register) accepts a hidden field question_id — expected to match the question session identifier (mybb_questionsessions.sid) — and validates the challenge answer without a fail-closed fallback for invalid identifiers. If the value is blank, forged, or expired, the request continues without a question-related error.

Patches

MyBB 1.8.(...) resolves this issue with the following changes:

  • Commit: https://github.com/mybb/mybb/commit/
    • .patch: https://github.com/mybb/mybb/commit/.patch

References

  • Release Notes: https://mybb.com/versions/1.8.(...)/

For more information

Go to mybb.com/security to report possible security concerns or to learn more about security research at MyBB.

Contact

The security team can be reached at security@mybb.com.

Database specific 
{
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "fixed": "1.8.40"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ],
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-636"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46482.json"
}
References

Affected packages

Git / github.com/mybb/mybb

Affected ranges

Type
GIT
Repo
https://github.com/mybb/mybb
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
bd2a3447939d3084a5926dd66ece04649e0e0d60
Fixed
e9942c6d19ac1709b3df7357cfb8810774c8d3ac
Database specific
Show details 
{
    "source": "REFERENCES"
}

Affected versions

Other
mybb_1800
mybb_1801
mybb_1804
mybb_1805
mybb_1806
mybb_1807
mybb_1808
mybb_1809
mybb_1810
mybb_1811
mybb_1812
mybb_1813
mybb_1814
mybb_1815
mybb_1815_build
mybb_1816
mybb_1816_build
mybb_1817
mybb_1817_build
mybb_1818
mybb_1818_build
mybb_1819
mybb_1819_build
mybb_1820
mybb_1820-rc
mybb_1820_build
mybb_1821
mybb_1821_build
mybb_1821pl1
mybb_1822
mybb_1822_build
mybb_1823
mybb_1823_build
mybb_1827
mybb_1827_build
mybb_1828
mybb_1828_build
mybb_1829
mybb_1831
mybb_1831_build
mybb_1832
mybb_1832_build
mybb_1833
mybb_1833_build
mybb_1834
mybb_1834_build
mybb_1835
mybb_1835_build
mybb_1836
mybb_1837
mybb_1837_build
mybb_1838
mybb_1838_build
mybb_1839
mybb_1839_build
mybb_1840_build

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46482.json"