CVE-2026-113866 — Account password sent unencrypted during Exchange account setup
When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request inc…
Published: 2026-10-20 · CVSS: 5.9 · CVSS 3.1
When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7