CVE-2026-3590
published 2026-04-15CVE-2026-3590: Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link…
PriorityP336medium6.5CVSS 3.1
AVNACLPRNUINSUCLILAN
EPSS
0.14%
4.2th percentile
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github.com | mattermost_mattermost-server | >= 10.11.0-rc1 < 10.11.13 | 10.11.13 |
| github.com | mattermost_mattermost-server | >= 11.3.0-rc1 < 11.3.3 | 11.3.3 |
| github.com | mattermost_mattermost-server | >= 11.4.0-rc1 < 11.4.3 | 11.4.3 |
| github.com | mattermost_mattermost-server | >= 11.5.0-rc1 < 11.5.0 | 11.5.0 |
| github.com | mattermost_mattermost_server_v8 | >= 8.0.0-20250721062209-4952acea88ce < 8.0.0-20250723052842-4cb8d8940332 | 8.0.0-20250723052842-4cb8d8940332 |
| mattermost | mattermost | 10.11.0 – 10.11.12 | — |
| mattermost | mattermost | 11.3.0 – 11.3.2 | — |
| mattermost | mattermost | 11.4.0 – 11.4.2 | — |
| mattermost | mattermost | 11.5.0 – 11.5.0 | — |
| mattermost | mattermost_server | >= 10.11.0 < 10.11.13 | 10.11.13 |
| mattermost | mattermost_server | >= 11.3.0 < 11.3.3 | 11.3.3 |
| mattermost | mattermost_server | >= 11.4.0 < 11.4.3 | 11.4.3 |
| mattermost | mattermost_server | >= 11.5.0 < 11.5.1 | 11.5.1 |
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GHSA
Mattermost has session spoofing due to lack of single-use consumption of guest magic link tokens enforcement
ghsa·2026-04-17
CVE-2026-3590 [MEDIUM] CWE-367 Mattermost has session spoofing due to lack of single-use consumption of guest magic link tokens enforcement
Mattermost has session spoofing due to lack of single-use consumption of guest magic link tokens enforcement
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests. Mattermost Advisory ID: MMSA-2026-00624.
GHSA
GHSA-mh4x-rmrx-3hp4: Mattermost versions 10
ghsa_unreviewed·2026-04-17
CVE-2026-3590 [MEDIUM] CWE-367 GHSA-mh4x-rmrx-3hp4: Mattermost versions 10
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624
VulDB
Mattermost up to 10.11.12/11.3.2/11.4.2/11.5.0 toctou (EUVD-2026-22915)
vuldb·2026-04-15·CVSS 6.5
CVE-2026-3590 [MEDIUM] Mattermost up to 10.11.12/11.3.2/11.4.2/11.5.0 toctou (EUVD-2026-22915)
A vulnerability marked as critical has been reported in Mattermost up to 10.11.12/11.3.2/11.4.2/11.5.0. Affected is an unknown function. This manipulation causes time-of-check time-of-use.
This vulnerability is tracked as CVE-2026-3590. The attack is possible to be carried out remotely. No exploit exists.
It is suggested to upgrade the affected component.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-3590 matterbridge: race condition in guest magic link authentication allows token reuse [fedora-all]
bugzilla·2026-04-15·CVSS 6.5
CVE-2026-3590 [MEDIUM] CVE-2026-3590 matterbridge: race condition in guest magic link authentication allows token reuse [fedora-all]
CVE-2026-3590 matterbridge: race condition in guest magic link authentication allows token reuse [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-3590 matterbridge: race condition in guest magic link authentication allows token reuse [epel-all]
bugzilla·2026-04-15·CVSS 6.5
CVE-2026-3590 [MEDIUM] CVE-2026-3590 matterbridge: race condition in guest magic link authentication allows token reuse [epel-all]
CVE-2026-3590 matterbridge: race condition in guest magic link authentication allows token reuse [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-3590 mattermost: race condition in guest magic link authentication allows token reuse
bugzilla·2026-04-15·CVSS 6.5
CVE-2026-3590 [MEDIUM] CVE-2026-3590 mattermost: race condition in guest magic link authentication allows token reuse
CVE-2026-3590 mattermost: race condition in guest magic link authentication allows token reuse
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624
2026-04-15
Published