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Fencer Intel
low 3.1

CVE-2026-4286 json

Playbooks Plugin fails to validate team transfers, allowing unauthorized removal of member access via playbook update

published 5mo ago modified 26d ago also GHSA-gvg4-jhmr-6j23 , GO-2026-5404 , EUVD-2026-30750

cvss
3.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to check if {{team_id}} was being changed when updating playbooks, allowing users with only {{Manage Playbook Configurations}} permission to change a playbook's team, bypassing manage members restriction via PUT api. Mattermost Advisory ID: MMSA-2025-00552

Patch / fix

  • go github.com/mattermost/mattermost/server/v8 10.11.14, 11.5.2
  • go github.com/mattermost/mattermost-plugin-playbooks 1.41.1-0.20260213020129-e1d6ec2c94e6
  • go github.com/mattermost/mattermost-server 10.11.14+incompatible, 11.5.2+incompatible
  • Mattermost Mattermost 10.11.14, 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

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5mo ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
GitHub 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/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
all versions
11.5.2
10.11.14
go github.com/mattermost/mattermost-plugin-playbooks
<1.41.1-0.20260213020129-e1d6ec2c94e6
1.41.1-0.20260213020129-e1d6ec2c94e6
go github.com/mattermost/mattermost-server
>=10.11.0+incompatible, <10.11.14+incompatible
>=11.5.0+incompatible, <11.5.2+incompatible
10.11.14+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

References

Sources

Fencer Intel 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.