CVE-2023-4478
Parameter tampering in the registration resulting in blocked accounts to be created
Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Parameter tampering in the registration resulting in blocked accounts to be created
Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.
- Record
CVE-2023-4478- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-74
- Updated
- 2026-11-02
EUVDEUVD-2023-54333
Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.
- Record
EUVD-2023-54333- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-65h8-5q72-mrp3
Mattermost fails to restrict which parameters' values it takes from the request during signup...
Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.
- Record
GHSA-65h8-5q72-mrp3- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-74
- Updated
- 2026-11-02
NVD
Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.
- Record
CVE-2023-4478- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-74
- Updated
- 2026-11-02
OSV
Parameter tampering in the registration resulting in blocked accounts to be created
Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.
- Record
CVE-2023-4478- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-74
- Updated
- 2026-11-02
OSVBIT-mattermost-2023-4478 No score
Mattermost fails to restrict which parameters' values it takes from the request during signup allowing an attacker to register users as inactive, thus blocking them from later accessing Mattermost without the system admin activating their accounts.
- Record
BIT-mattermost-2023-4478- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mattermostBitnami |
before 7.8.9, 7.9.0 up to 7.10.5, 8.0.0 to 8.0.0 | 7.8.97.10.5 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-4478 is a medium vulnerability (CVSS 4.3) in Mattermost, published August 25, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.50%, the 43rd percentile. Fixed in mattermost 7.8.9.