Public mode

No access to your tenant or devices. Every item links to its source. What this means

CVE-2026-15814

Uploading a crafted image causes excessive memory allocation in the Mattermost Server

CVSS 3.1 6.5 MEDIUMCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-15814

Published

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploaded image files which allows an authenticated user to cause excessive server memory consumption and potential denial of service via uploading a specially crafted image as a profile picture, channel file attachment, team icon, or custom brand image. Mattermost Advisory ID: MMSA-2026-00719

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-15814

Published

Mattermost

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "defaultStatus": "unaffected",
                    "product": "Mattermost",
                    "vendor": "Mattermost",
                    "versions": [
                        {
                            "lessThanOrEqual": "11.9.0",
                            "status": "affected",
                            "version": "11.9.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThanOrEqual": "11.8.4",
                            "status": "affected",
                            "version": "11.8.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThanOrEqual": "11.7.7",
                            "status": "affected",
                            "version": "11.7.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThanOrEqual": "10.11.22",
                            "status": "affected",
                            "version": "10.11.0",
                            "versionType": "semver"
                        },
                        {
                            "version": "11.10.0",
                            "status": "unaffected"
                        },
                        {
                            "version": "11.9.1",
                            "status": "unaffected"
                        },
                        {
                            "version": "11.8.5",
                            "status": "unaffected"
                        },
                        {
                            "version": "11.7.8",
                            "status": "unaffected"
                        },
                        {
                            "version": "10.11.23",
                            "status": "unaffected"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON