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 affects Thunderbird < 149 and Thunderbird < 140.9.
CVSS Metrics
- Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
- Attack Vector
- network
- Complexity
- high
- Privileges
- none
- User Action
- none
- Scope
- unchanged
- Confidentiality
- high
- Integrity
- none
- Availability
- high
- Weaknesses
- CWE-126
Metadata
- Primary Vendor
- MOZILLA
- Published
- 3/24/2026
- Last Modified
- 3/27/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
mozilla : thunderbirdmozilla : thunderbird
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