Description
When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network shares. A malicious server, or a network attacker when the lookup used plain HTTP, could make Thunderbird subscribe to such a location. On Windows this could leak the user's NTLM credentials to an attacker-controlled host on every calendar refresh, and changes to the calendar could be written to the attacker's share or overwrite a local file. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.
Published: 2026-10-27
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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History

Tue, 27 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Description When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network shares. A malicious server, or a network attacker when the lookup used plain HTTP, could make Thunderbird subscribe to such a location. On Windows this could leak the user's NTLM credentials to an attacker-controlled host on every calendar refresh, and changes to the calendar could be written to the attacker's share or overwrite a local file. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.
Title Calendar discovery accepted local file and remote network share locations
References

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-10-27T18:27:49.964Z

Reserved: 2026-10-27T18:16:30.717Z

Link: CVE-2026-118177

cve-icon Vulnrichment

No data.

cve-icon NVD

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cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses

No weakness.