Medium severity6.5NVD Advisory· Published May 22, 2026· Updated Jul 23, 2026
CVE-2026-5755
CVE-2026-5755
Description
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.2, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the TIFF IFD offset in the image header before allocating memory, which allows authenticated users with file upload or posting permissions to cause a denial of service (server OOM) via uploading a crafted TIFF file or posting a URL that serves one.. Mattermost Advisory ID: MMSA-2026-00648
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
github.com/mattermost/mattermost-serverGo | >= 11.6.0, < 11.6.1 | 11.6.1 |
github.com/mattermost/mattermost-serverGo | >= 11.5.0, < 11.5.4 | 11.5.4 |
github.com/mattermost/mattermost-serverGo | >= 11.4.0, < 11.4.5 | 11.4.5 |
github.com/mattermost/mattermost-serverGo | >= 10.11.0, < 10.11.15 | 10.11.15 |
Affected products
3<=11.6.0, <=11.5.2, <=11.5.3, <=11.4.4, <=10.11.14+ 1 more
- (no CPE)range: <=11.6.0, <=11.5.2, <=11.5.3, <=11.4.4, <=10.11.14
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*range: >=10.11.0,<10.11.15
- osv-coordsRange: < 0.0.20260723T184607-160000.1.1
Patches
Vulnerability mechanics
References
4- github.com/advisories/GHSA-37j2-3vv8-cf24ghsaADVISORY
- mattermost.com/security-updatesnvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-5755ghsaADVISORY
- github.com/mattermost/mattermost/commit/d37c2d9d50b50963dabd92153adf7ed52016769aghsaWEB
News mentions
0No linked articles in our index yet.