CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-20719
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595
Severity
- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 29% of CVEs (scores of 2026-10-31)
- CWE
- CWE-754
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-86vc-mg26-fj6x | Go | github.com/mattermost/mattermost/server/v8 | >=11.4.0-rc1 <11.4.1 | 11.4.1 |
| GHSA-86vc-mg26-fj6x | Go | github.com/mattermost/mattermost/server/v8 | >=11.3.0-rc1 <11.3.2 | 11.3.2 |
| GHSA-86vc-mg26-fj6x | Go | github.com/mattermost/mattermost/server/v8 | >=11.2.0-rc1 <11.2.4 | 11.2.4 |
| GHSA-86vc-mg26-fj6x | Go | github.com/mattermost/mattermost/server/v8 | >=8.0.0-20260105080200-d27a2195068d <8.0.0-20260217110922-b7d4a1f1f59b | 8.0.0-20260217110922-b7d4a1f1f59b |
| GHSA-86vc-mg26-fj6x | Go | github.com/mattermost/mattermost/server/v8 | >=10.11.0-rc1 <10.11.2 | 10.11.2 |
| GO-2026-5245 | Go | github.com/mattermost/mattermost-server | >=10.11.0-rc1+incompatible <10.11.2+incompatible >=11.2.0-rc1+incompatible <11.2.4+incompatible >=11.3.0-rc1+incompatible <11.3.2+incompatible >=11.4.0-rc1+incompatible <11.4.1+incompatible | 10.11.2+incompatible, 11.2.4+incompatible, 11.3.2+incompatible, 11.4.1+incompatible |
| GO-2026-5245 | Go | github.com/mattermost/mattermost-server/v5 | all versions | no fix published |
| GO-2026-5245 | Go | github.com/mattermost/mattermost-server/v6 | all versions | no fix published |
| GO-2026-5245 | Go | github.com/mattermost/mattermost/server/v8 | >=8.0.0-20260105080200-d27a2195068d <8.0.0-20260217110922-b7d4a1f1f59b | 8.0.0-20260217110922-b7d4a1f1f59b |