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Tue, 10 Nov 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | If an attacker was able to perform a man-in-the-middle attack on an SMTP or POP3 server connection using STARTTLS, the attacker could inject server responses before the TLS handshake completed. Thunderbird would process these responses after the handshake, as if they had been received from the server over the encrypted connection. This could be used to make Thunderbird report a different outcome for sending or fetching mail, and to show attacker-controlled text in error messages. The encrypted connection itself was not compromised, and credentials were not exposed. Connections using SSL/TLS instead of STARTTLS were not affected. This vulnerability was fixed in Thunderbird 160. | If an attacker was able to perform a man-in-the-middle attack on an SMTP or POP3 server connection using STARTTLS, the attacker could inject server responses before the TLS handshake completed. Thunderbird would process these responses after the handshake, as if they had been received from the server over the encrypted connection. This could be used to make Thunderbird report a different outcome for sending or fetching mail, and to show attacker-controlled text in error messages. The encrypted connection itself was not compromised, and credentials were not exposed. Connections using SSL/TLS instead of STARTTLS were not affected. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7. |
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Tue, 10 Nov 2026 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | If an attacker was able to perform a man-in-the-middle attack on an SMTP or POP3 server connection using STARTTLS, the attacker could inject server responses before the TLS handshake completed. Thunderbird would process these responses after the handshake, as if they had been received from the server over the encrypted connection. This could be used to make Thunderbird report a different outcome for sending or fetching mail, and to show attacker-controlled text in error messages. The encrypted connection itself was not compromised, and credentials were not exposed. Connections using SSL/TLS instead of STARTTLS were not affected. This vulnerability was fixed in Thunderbird 160. | |
| Title | SMTP and POP3 response injection when using STARTTLS | |
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Subscriptions
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Status: PUBLISHED
Assigner: mozilla
Published:
Updated: 2026-11-10T20:24:07.977Z
Reserved: 2026-11-10T18:59:56.332Z
Link: CVE-2026-126135
No data.
Status : Received
Published: 2026-11-10T19:21:14.203
Modified: 2026-11-10T19:21:14.203
Link: CVE-2026-126135
No data.
OpenCVE Enrichment
No data.
No weakness.