CVE-2021-37863
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which...
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
- Record
CVE-2021-37863- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2021-24341
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
- Record
EUVD-2021-24341- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-7523-wx28-g6xf No score
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which...
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
- Record
GHSA-7523-wx28-g6xf- Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
- Record
CVE-2021-37863- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L - CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:N/A:P - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
- Record
CVE-2021-37863- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVBIT-mattermost-2021-37863 No score
Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
- Record
BIT-mattermost-2021-37863- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mattermostBitnami |
before 6.0.1 | 6.0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-37863 is a low vulnerability (CVSS 3.5) in Mattermost, published December 17, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.86%, the 58th percentile. Fixed in mattermost 6.0.1.