CVE-2026-25783 — Denial of service via malformed User-Agent header in getBrowserVersion
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 …
Published: 2026-03-16 · CVSS: 4.3 · CVSS 3.1
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
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7