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CVE-2026-4371
Published: Mar 24, 2026
Modified: Apr 13, 2026
PUBLISHED
Description
A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.
| Vendor | Product | Versions |
|---|---|---|
Mozilla | Thunderbird | unaffected 140.9 - <= 140.*unaffected 149 - <= * |
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