thunderbird security update (CVE-2026-103500)
Description
Mozilla Thunderbird contained a critical heap buffer overflow vulnerability (CVE-2026-103500) triggered by opening an email of size 2GB or larger. This flaw allows remote attackers to cause severe impact including full confidentiality, integrity, and availability compromise. The issue was 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-SP3Run 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 that occurs when a user opens an email message that is 2GB or larger. This vulnerability allows an attacker to execute arbitrary code or cause a denial of service due to memory corruption. The flaw was addressed by Mozilla in Thunderbird versions 157, 140.17, and 153.4, which contain the necessary security fixes.
Potential Impact
Successful exploitation of this vulnerability can lead to complete system compromise, including unauthorized disclosure of information, modification of data, and disruption of service. The CVSS v3.1 score of 9.8 reflects the critical severity and the fact that no privileges or user interaction are required for exploitation beyond opening a crafted email.
Mitigation Recommendations
A security update is available and should be applied immediately. Users should upgrade to Thunderbird version 157, 140.17, 153.4, or later to remediate this vulnerability. No additional mitigations are specified by the vendor advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- OESA-2026-4457
- Osv Schema Version
- 1.7.2
- Ecosystems
- ["openEuler:24.03-LTS-SP3"]
- Database Specific Severity
- Critical
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ada44d14d27ba8daa6a4a14
Added to database: 10/22/2026, 17:16:01 UTC
Last enriched: 10/22/2026, 17:22:33 UTC
Last updated: 10/23/2026, 00:15:13 UTC
Views: 2
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