When a user explicitly requested Thunderbird to decrypt an inline OpenPGP message that was embedded in a text section of an email that was formatted and styled with HTML and CSS, then the decrypted contents were rendered in a context in which the CSS styles from the outer messages were active. If the user had additionally allowed loading of the remote content referenced by the outer email message, and the email was crafted by the sender using a combination of CSS rules and fonts and animations, then it was possible to extract the secret contents of the email. This vulnerability affects Thunderbird < 147.0.1 and Thunderbird < 140.7.1.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 4.3, indicating it can be exploited remotely over the network with relatively low complexity though user interaction is required and does not require pre-existing privileges . The vulnerability impacts limited data confidentiality, for affected systems. Impacting 1 product from mozilla organizations running these solutions should prioritize assessment and patching.
Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2026-01-28T08:16:03.113
2026-02-04T10:16:04.550
Modified
CVSSv3.1: 4.3 (MEDIUM)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | mozilla | thunderbird | < 140.7.1 | Yes |
| Application | mozilla | thunderbird | < 147.0.1 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For mozilla's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.