Out of bounds read in IMAP parsing_CVE-2026-4371

7.4 / 10

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

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.

Basic Information

ID CVE-2026-4371

Source mozilla

Published Mar 24, 2026 at 20:27

Modified Mar 25, 2026 at 16:24

Affected Product

Vendor Mozilla

Product Thunderbird

Version unspecified

Affected Versions Mozilla Thunderbird unspecified
Mozilla Thunderbird unspecified

CWE Classification

CWE-126

References

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    "lastseen": "",
    "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.",
    "published": "2026-03-24T20:27:15.198Z",
    "modified": "2026-03-25T16:24:50.635Z",
    "type": "cve",
    "title": "Out of bounds read in IMAP parsing",
    "source": "mozilla",
    "references": "https://bugzilla.mozilla.org/show_bug.cgi?id=2023493\nhttps://www.mozilla.org/security/advisories/mfsa2026-23/\nhttps://www.mozilla.org/security/advisories/mfsa2026-24/",
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    "product": "Thunderbird",
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