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Fencer Vulns
medium 6.5

CVE-2026-6345 json

Prevent password disclosure and force reset during Slack import

published 2026-05-18 5 mo ago modified 2026-10-14 25 d ago also GHSA-wvgv-4fc3-2rcp , GO-2026-5727 , EUVD-2026-30756

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail prevent disclosure of created user password which allows a malicious attacker to impersonate a user via the use of some of those passwords.. Mattermost Advisory ID: MMSA-2026-00614

Patch / fix

  • go github.com/mattermost/mattermost/server/v8 8.0.0-20260311102650-3057ae7e83e9, 10.11.14, 11.4.4, 11.5.2
  • go github.com/mattermost/mattermost-server 5.3.2-0.20260311102650-3057ae7e83e9, 10.11.14+incompatible, 11.4.4+incompatible, 11.5.2+incompatible
  • Mattermost Mattermost 10.11.14, 11.4.4, 11.5.2, 11.6.0
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
5 mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/mattermost/mattermost/server/v8
>=11.5.0, <11.5.2
>=10.11.0, <10.11.14
>=11.4.0, <11.4.4
<8.0.0-20260311102650-3057ae7e83e9
11.5.2
10.11.14
11.4.4
8.0.0-20260311102650-3057ae7e83e9
go github.com/mattermost/mattermost-server
<5.3.2-0.20260311102650-3057ae7e83e9
>=10.11.0+incompatible, <10.11.14+incompatible
>=11.4.0+incompatible, <11.4.4+incompatible
>=11.5.0+incompatible, <11.5.2+incompatible
5.3.2-0.20260311102650-3057ae7e83e9
10.11.14+incompatible
11.4.4+incompatible
11.5.2+incompatible
go github.com/mattermost/mattermost-server/v5
all versions
no fix listed
go github.com/mattermost/mattermost-server/v6
all versions
no fix listed

Affected products

  • Mattermost Mattermost

Classification

Weakness
  • CWE-522 Insufficiently Protected Credentials

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.