CVE-2023-5967
Denial of Service via crashing the Calls Plugin
Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin
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
Denial of Service via crashing the Calls Plugin
Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin
- Record
CVE-2023-5967- 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-754
- Updated
- 2026-11-02
EUVDEUVD-2023-3066
Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin
- Record
EUVD-2023-3066- 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-xvq6-h898-wcj8
Mattermost denial of service vulnerability
Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin
- Record
GHSA-xvq6-h898-wcj8- 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-754
- Updated
- 2026-11-02
NVD
Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin
- Record
CVE-2023-5967- 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-754
- Updated
- 2026-11-02
OSV
Denial of Service via crashing the Calls Plugin
Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin
- Record
CVE-2023-5967- 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-754
- Updated
- 2026-11-02
OSVGHSA-xvq6-h898-wcj8
Mattermost denial of service vulnerability
Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin
- Record
GHSA-xvq6-h898-wcj8- 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-754
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/mattermost/mattermost-server/v6Go |
before 7.8.12 | 7.8.12 |
github.com/mattermost/mattermost/server/v8Go |
8.0.0 up to 8.0.4 | 8.0.4 |
github.com/mattermost/mattermost/server/v8Go |
8.1.0 up to 8.1.3 | 8.1.3 |
github.com/mattermost/mattermost/server/v8Go |
9.0.0 to 9.0.0 | 9.0.1 |
github.com/mattermost/mattermost/server/v8Go |
9.0.0 up to 9.0.1 | 9.0.1 |
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-2023-5967 is a medium vulnerability (CVSS 4.3) in Mattermost, published November 6, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.61%, the 49th percentile. Fixed in github.com/mattermost/mattermost-server/v6 7.8.12.