Skip to content
CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-126133

Calendar server credentials could be sent to an HTTP proxy

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
mozilla

Description

When a CalDAV or ICS calendar was accessed through an HTTP proxy that requested authentication, Thunderbird could answer the proxy with the calendar server's username and password. This affected both setting up a new calendar and syncing existing calendars, where a saved password could be sent without any user interaction. A malicious or compromised proxy could use this to obtain the calendar credentials, even for calendars served over HTTPS. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Mozilla Thunderbird

  • 153.7 to ≤ 153.*unaffected
  • 160 to ≤ *unaffected

References