CVE-2026-5755
Mattermost doesn't validate the TIFF IFD offset in the image header before allocating memory in github.com/mattermost/mattermost-server
6.5
MEDIUM
CVSS 3.1
EPSS 0.24%
Description
Mattermost doesn't validate the TIFF IFD offset in the image header before allocating memory in github.com/mattermost/mattermost-server
How to fix CVE-2026-5755
To remediate CVE-2026-5755, upgrade the affected package to a fixed version below.
- Go/github.com/mattermost/mattermost-server—upgrade to 11.6.1 or later
- —upgrade to 10.11.15+incompatible or later
Is CVE-2026-5755 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- >= 11.6.0, < 11.6.1
- >= 10.11.0+incompatible, < 10.11.15+incompatible, >= 11.4.0+incompatible, < 11.4.5+incompatible, >= 11.5.0+incompatible, < 11.5.4+incompatible, >= 11.6.0+incompatible, < 11.6.1+incompatible
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |