CVE-2021-37860 json
Cross-site Scripting in Mattermost
published 2021-09-22 5 y ago modified 2026-06-17 4 mo ago also GHSA-hv5f-73mr-7vvj , GO-2022-0604 , EUVD-2021-2078
- cvss
- 3.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 50%
- public exploits
- 0
- none known
Summary
Mattermost 5.38 and earlier fails to sufficiently sanitize clipboard contents, which allows a user-assisted attacker to inject arbitrary web script in product deployments that explicitly disable the default CSP.
Patch / fix
- go github.com/mattermost/mattermost-server/v5 5.39.0
- mattermost Arch Linux 5.39.0-1
arch linux advisories AVG-2416
Exploit prediction
0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N |
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 2.6 | AV:N/AC:H/Au:N/C:N/I:P/A:N |
| GitHub | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost-server/v5 | <5.39.0 |
5.39.0 |
| go | github.com/mattermost/mattermost-server | all versions |
no fix listed |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
mattermost.com
/security-updates/
vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-37860
advisory
-
docs.mattermost.com
/install/self-managed-changelog.html#release-v5-39-quality-release
web
-
github.com
/mattermost/mattermost-server
web
-
mattermost.com
/security-updates
web
-
github.com
/advisories/GHSA-hv5f-73mr-7vvj
advisory
Sources
- CVE List CVE-2021-37860
- GitHub Advisory GHSA-hv5f-73mr-7vvj
- NVD CVE-2021-37860
- OSV GO-2022-0604
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.