CVE-2021-26036
[20210702] - Core - DoS through usergroup table manipulation
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead to a broken usergroups table.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead to a broken usergroups table.
- Record
CVE-2021-26036- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-20
- Updated
- 2026-11-02
CVE List No score
[20210702] - Core - DoS through usergroup table manipulation
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead to a broken usergroups table.
- Record
CVE-2021-26036- Updated
- 2026-11-02
EUVDEUVD-2021-12859 No score
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead to a broken usergroups table.
- Record
EUVD-2021-12859- Updated
- 2026-11-02
GitHub AdvisoriesGHSA-g983-3grj-v7qw No score
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead...
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead to a broken usergroups table.
- Record
GHSA-g983-3grj-v7qw- Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead to a broken usergroups table.
- Record
CVE-2021-26036- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVBIT-joomla-2021-26036 No score
[20210702] - Core - DoS through usergroup table manipulation
An issue was discovered in Joomla! 2.5.0 through 3.9.27. Missing validation of input could lead to a broken usergroups table.
- Record
BIT-joomla-2021-26036- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
joomlaBitnami |
2.5.0 to 3.9.27 | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-26036 is a high vulnerability (CVSS 7.5) in Joomla Joomla\!, published July 7, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.22%, the 69th percentile. No source names a fixed version.