cve.bz

CVE-2025-20621

7.5 highEPSS 0.5%

High (7.5) in mattermost mattermost server. EPSS 0.5% 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 handle posts with attachments containing fields that cannot be cast to a String, which allows an attacker to cause the webapp to crash via creating and sending such a post to a channel.

Severity

CVSS 3.1

7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.5% chance of exploitation in the next 30 days; higher than 41% of CVEs (scores of 2026-10-31)
CWE
CWE-1287
Published
Modified
Record from
the NVD, synced

Affected

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-w6xh-c82w-h997Gogithub.com/mattermost/mattermost/server/v8>=10.2.0 <10.2.110.2.1
GHSA-w6xh-c82w-h997Gogithub.com/mattermost/mattermost/server/v8>=10.1.0 <10.1.410.1.4
GHSA-w6xh-c82w-h997Gogithub.com/mattermost/mattermost/server/v8>=10.0.0 <10.0.410.0.4
GHSA-w6xh-c82w-h997Gogithub.com/mattermost/mattermost/server/v8>=9.11.0 <9.11.69.11.6
GHSA-w6xh-c82w-h997Gogithub.com/mattermost/mattermost/server/v8<8.0.0-20241127161322-25ff7a3779a58.0.0-20241127161322-25ff7a3779a5
GO-2025-3407Gogithub.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-2025-3407Gogithub.com/mattermost/mattermost-server/v5all versionsno fix published
GO-2025-3407Gogithub.com/mattermost/mattermost-server/v6all versionsno fix published
GO-2025-3407Gogithub.com/mattermost/mattermost/server/v8<8.0.0-20241127161322-25ff7a3779a58.0.0-20241127161322-25ff7a3779a5

References

Check your stackJSON