CVE-2023-5333
Denial of Service via multiple identical User IDs in /api/v4/users/ids
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
4.3
Denial of Service via multiple identical User IDs in /api/v4/users/ids
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.
- Record
CVE-2023-5333- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-400
- Updated
- 2026-11-02
EUVDEUVD-2023-57650
4.3
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.
- Record
EUVD-2023-57650- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-w28r-7qw2-ghqc
4.3
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to...
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.
- Record
GHSA-w28r-7qw2-ghqc- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-400
- Updated
- 2026-11-02
NVD
4.3
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.
- Record
CVE-2023-5333- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
OSV
4.3
Denial of Service via multiple identical User IDs in /api/v4/users/ids
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.
- Record
CVE-2023-5333- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-400
- Updated
- 2026-11-02
OSVBIT-mattermost-2023-5333 No score
Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.
- Record
BIT-mattermost-2023-5333- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mattermostBitnami |
before 7.8.11, 8.0.0 up to 8.0.3, 8.1.0 up to 8.1.2 | 7.8.118.0.38.1.2 |
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-2023-5333 is a medium vulnerability (CVSS 4.3) in Mattermost, published October 9, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.60%, the 48th percentile. Fixed in mattermost 7.8.11.