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Fencer Vulns
low 3.7

CVE-2018-21249 json

An issue was discovered in Mattermost Server before 5.3.0.

published 2020-06-19 6 y ago modified 2026-06-17 4 mo ago also EUVD-2018-13764

cvss
3.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

An issue was discovered in Mattermost Server before 5.3.0. It mishandles timing.

Patch / fix

  • mattermost mattermost_server 5.3.0

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

References

Sources

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.