CVE-2026-25783

Discovered by AISLEPUBLISHEDCWE-1287

Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate User-Agent header tokens which allows an authenticated attacker to cause a request panic via a specially crafted User-Agent header. Mattermost Advisory ID: MMSA-2026-00586

CVSS Base Scores

CVSS v3.1(Primary)
4.3

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Affected Products

VendorProductVersionStatus
MattermostMattermost11.3.0affected
MattermostMattermost11.2.0unaffected
MattermostMattermost10.11.0—
MattermostMattermost11.4.0—
MattermostMattermost11.3.1—
MattermostMattermost11.2.3—
MattermostMattermost10.11.11—

Credits

  • winfunc(finder)

Solutions

Update Mattermost to versions 11.4.0, 11.3.1, 11.2.3, 10.11.11 or higher.

References