thunderbird security update (CVE-2026-103500)
Description
A critical heap buffer overflow vulnerability exists in Mozilla Thunderbird when opening emails of size 2GB or larger. This flaw allows an attacker to cause severe memory corruption, potentially leading to full compromise. The issue is fixed in Thunderbird versions 157, 140.17, and 153.4.
CVSS v3.1
Score 9.8critical
Affected software
pkg:rpm/openEuler/thunderbird&distro=openEuler-24.03-LTS-SP4Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-103500 is a heap buffer overflow vulnerability in Mozilla Thunderbird triggered by opening an email message that is 2GB or larger. This vulnerability allows an attacker to cause memory corruption, which can lead to arbitrary code execution or application crash. The flaw was addressed by Mozilla in Thunderbird versions 157, 140.17, and 153.4.
Potential Impact
Successful exploitation can result in complete compromise of the affected Thunderbird client, including execution of arbitrary code, data corruption, or denial of service. The CVSS v3.1 score of 9.8 reflects the critical nature of this vulnerability with network attack vector, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A security update is available and should be applied immediately. Users and administrators should upgrade Thunderbird to version 157, 140.17, 153.4, or later to remediate this vulnerability.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- OESA-2026-4458
- Osv Schema Version
- 1.7.2
- Ecosystems
- ["openEuler:24.03-LTS-SP4"]
- Database Specific Severity
- Critical
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ada44d14d27ba8daa6a4a13
Added to database: 10/22/2026, 17:16:01 UTC
Last enriched: 10/22/2026, 17:22:30 UTC
Last updated: 10/23/2026, 00:15:13 UTC
Views: 2
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