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.
Metrics
Affected Vendors & Products
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
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References
History
Tue, 10 Nov 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | 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. |
| References |
|
Tue, 10 Nov 2026 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Calendar server credentials could be sent to an HTTP proxy | |
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: mozilla
Published:
Updated: 2026-11-10T20:24:06.988Z
Reserved: 2026-11-10T18:59:53.798Z
Link: CVE-2026-126133
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2026-11-10T19:21:13.983
Modified: 2026-11-10T21:19:27.670
Link: CVE-2026-126133
Redhat
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OpenCVE Enrichment
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Weaknesses
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