CVE-2026-4274Disclosure(mattermost / mattermost_server)

LOWCVSS 5.4 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574

0.0/ 10 priority

Sources & remediation

Vendor / third-party advisories
Weakness type (CWE)
CWE-863

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • mattermost_server

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • Technical details provided in 1 signal
  • Disclosure: 1 classified signal
  • 1 total mentions across 1 day

Affected systems

Vendors
Products
mattermost_server

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-03-26: 1Technical Details · 2026-03-26: 103-26
Signal classification1 categories
Disclosure
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • CVE@CVEnew
    Disclosure

    CVE-2026-4274 Mattermost versions 11.2.x &lt;= 11.2.2, 10.11.x &lt;= 10.11.10, 11.4.x &lt;= 11.4.0, 11.3.x &lt;= 11.3.1 fail to restrict team-level access when processing membership sync from a … https://www.cve.org/CVERecord?id=CVE-2026-4274

    Post summary

    The post merely cites CVE‑2026‑4274, describing an access control flaw in Mattermost during membership sync, without providing evidence of exploitation, PoC, or fixes.

    0001068
    56.8K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appmattermostmattermost_server---

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