cve.bz

CVE-2025-21088

6.5 mediumEPSS 0.6%

Medium (6.5) in mattermost mattermost server. EPSS 0.6% chance of exploitation in the next 30 days. Fixed in github.com/mattermost/mattermost/server/v8 10.0.4, 10.1.4, 10.2.1.

Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly validate the style of proto supplied to an action's style in post.props.attachments, which allows an attacker to crash the frontend via crafted malicious input.

Severity

CVSS 3.1

6.5 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.6% chance of exploitation in the next 30 days; higher than 47% of CVEs (scores of 2026-10-31)
CWE
CWE-704
Published
Modified
Record from
the NVD, synced

Affected

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-8j3q-gc9x-7972Gogithub.com/mattermost/mattermost/server/v8>=10.2.0 <10.2.110.2.1
GHSA-8j3q-gc9x-7972Gogithub.com/mattermost/mattermost/server/v8>=10.1.0 <10.1.410.1.4
GHSA-8j3q-gc9x-7972Gogithub.com/mattermost/mattermost/server/v8>=10.0.0 <10.0.410.0.4
GHSA-8j3q-gc9x-7972Gogithub.com/mattermost/mattermost/server/v8>=9.11.0 <9.11.69.11.6
GHSA-8j3q-gc9x-7972Gogithub.com/mattermost/mattermost/server/v8<8.0.0-20241127161322-25ff7a3779a58.0.0-20241127161322-25ff7a3779a5
GO-2025-3393Gogithub.com/mattermost/mattermost-server>=9.11.0+incompatible <9.11.6+incompatible
>=10.0.0+incompatible <10.0.4+incompatible
>=10.1.0+incompatible <10.1.4+incompatible
>=10.2.0+incompatible <10.2.1+incompatible		9.11.6+incompatible, 10.0.4+incompatible, 10.1.4+incompatible, 10.2.1+incompatible
GO-2025-3393Gogithub.com/mattermost/mattermost-server/v5all versionsno fix published
GO-2025-3393Gogithub.com/mattermost/mattermost-server/v6all versionsno fix published
GO-2025-3393Gogithub.com/mattermost/mattermost/server/v8<8.0.0-20241127161322-25ff7a3779a58.0.0-20241127161322-25ff7a3779a5

References

Check your stackJSON