CVE-2021-27890 in the critical feed json
SQL Injection vulnerablity in MyBB before 1.8.26 via theme properties included in theme XML files.
published 2021-03-15 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-14627
- cvss
- 8.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 10.7%
- EPSS 10.7% chance of exploitation in 30 days, percentile 95%
- public exploits
- 1
- Exploit-DB
Summary
SQL Injection vulnerablity in MyBB before 1.8.26 via theme properties included in theme XML files.
Patch / fix
Timeline
- Published
- First public exploit (EDB-49696)
Exploit prediction
10.68% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- EDB-49696 MyBB 1.8.25 - Chained Remote Command Execution webapps, 2021-03-22
- blog.sonarsource.com https://blog.sonarsource.com/mybb-remote-code-execution-chain referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-89 Improper Neutralization of Special Elements used in an SQL Command
References
-
github.com
/mybb/mybb/security/advisories/GHSA-r34m-ccm8-mfhq
patch, release-notes, third-party-advisory
-
blog.sonarsource.com
/mybb-remote-code-execution-chain
exploit, third-party-advisory
-
packetstormsecurity.com
/files/161908/MyBB-1.8.25-Remote-Command-Execution.html
third-party-advisory, vdb-entry
Sources
- CVE List CVE-2021-27890
- NVD CVE-2021-27890
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.