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.
Published:
2026-11-10
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mozilla | Thunderbird | affected |
|
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Remediation
No remediation available yet.
Tracking
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Advisories
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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 |
|
Subscriptions
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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 : Received
Published: 2026-11-10T19:21:13.983
Modified: 2026-11-10T19:21:13.983
Link: CVE-2026-126133
Redhat
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OpenCVE Enrichment
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Weaknesses
No weakness.