CVE-2026-4371

HighCVSS 7.4/10Last modified Jul 15, 2026

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.

Metrics

CVSS 3.1 7.4/10CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

Weakness enumeration

CWE-126CWE-130

Affected software

No affected versions have been published.

Timeline

Published
Mar 24, 2026
Last modified
Jul 15, 2026
NVD status
Modified

Related CVEs from 2026

CVE-2026-437109.8The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. ACVE-2026-437117.8A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.6 and iCVE-2026-437126.5The issue was addressed with improved memory handling. This issue is fixed in Safari 26.5.2, iOS 26.5.2 and iPadOS 26.5.2, macOS Tahoe 26.5.CVE-2026-437136.5A permissions issue was addressed with additional restrictions. This issue is fixed in Safari 26.5.2, iOS 26.5.2 and iPadOS 26.5.2, macOS TaCVE-2026-437145.5The issue was addressed with improved input sanitization. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.6 and iPadOS 26.6, mCVE-2026-437158.8A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 26.5.2, iOS 26.5.2 and iPadOS 26.5.2, iOCVE-2026-437166.5The issue was addressed with improved memory handling. This issue is fixed in Safari 26.5.2, iOS 26.5.2 and iPadOS 26.5.2, macOS Tahoe 26.5.CVE-2026-437176.5A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 26.5.2, iOS 18.7.10 and iPadOS 18.7.10, CVE-2026-437186.5A stack overflow was addressed with improved input validation. This issue is fixed in Safari 26.5.2, iOS 26.5.2 and iPadOS 26.5.2, macOS TahCVE-2026-437196.5A use-after-free issue was addressed with improved memory management. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOSCVE-2026-43727.8A critical remote code execution vulnerability exists in all versions of the HuggingFace transformers library prior to version 5.3.0. The vuCVE-2026-437206.5A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 26.5.2, iOS 18.7.10 and iPadOS 18.7.10,
CVE-2026-4371: High severity, CVSS 7.4 | Vulnix