CVE-2026-118180
Matrix homeserver could redirect the chat session to a local file or network share
No known exploitation. EPSS puts it in the 7th percentile. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- Mozilla ThunderbirdFixed builds153.6, 159Stated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
When logging in to a Matrix account, Thunderbird used the homeserver address provided in the server's login response without validating it. A malicious or compromised homeserver could provide a file: URL, causing Thunderbird to send all further Matrix requests of that session to local files or, on Windows, to an attacker-controlled network share, which could leak the user's NTLM credentials. The NTLM credential leak only affects Thunderbird on Windows. Other operating systems are unaffected. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.2% chance of exploitation activity in the next 30 days, which ranks it in the 7th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
3 events over 1 day, from the signal feeds we watch.
- Record updated
- Publishedrecord updated
Affected products
Sources
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