PT-2026-28642 · Mattermost · Mattermost

Daw10 · Publicado 2026-03-26 · Atualizado 2026-03-26 · CVE-2026-4274

Positive Technologies (AI Summary)

CVSS v3.1

5.4

Média

Vetor base

AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions Mattermost versions 10.11.0 through 10.11.10 Mattermost versions 11.2.0 through 11.2.2 Mattermost versions 11.3.0 through 11.3.1 Mattermost versions 11.4.0

Description The software does not properly restrict team-level access when processing membership synchronization from a remote cluster. This allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel. This is achieved by sending crafted membership synchronization messages that trigger team membership assignment.

Recommendations Update Mattermost to a version later than 10.11.10. Update Mattermost to a version later than 11.2.2. Update Mattermost to a version later than 11.3.1. Update Mattermost to a version later than 11.4.0.

Correção

Incorrect Authorization

Enumeração de Fraquezas

CWE-863

Identificadores relacionados

CVE-2026-4274

GHSA-G7FP-CQJ5-X8HF

Produtos afetados

Mattermost

Referências · 6

• https://github.com/mattermost/mattermost · Nota
• https://mattermost.com/security-updates · Aviso do Fabricante
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-4274 · Nota
• https://twitter.com/CVEnew/status/2037137711186764276 · Publicação no Twitter
• https://nvd.nist.gov/vuln/detail/CVE-2026-4274 · Nota de Segurança
• https://osv.dev/vulnerability/GHSA-g7fp-cqj5-x8hf · Aviso do Fabricante