XSS in Mattermost

CVE-2021-37859

Fixed a bypass for a reflected cross-site scripting vulnerability affecting OAuth-enabled instances of Mattermost.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.033 (88.0th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 88.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-37859: held from 0.033 to 0.033.

EPSS over last 30 days · oldest: 0.033 · newest: 0.033 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-37859?
CVE-2021-37859 is a high-severity vulnerability in Mattermost, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2021-08-05.
How severe is CVE-2021-37859?
High severity. CVSS v3 base score is 7.1 out of 10.
Is CVE-2021-37859 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.