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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-0818 Detail

Current Description

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.


View Analysis Description

Metrics

 
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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
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N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=1881530 Mozilla Corporation Permissions Required 
https://lists.debian.org/debian-lts-announce/2026/02/msg00005.html CVE
https://www.mozilla.org/security/advisories/mfsa2026-07/ Mozilla Corporation Vendor Advisory 
https://www.mozilla.org/security/advisories/mfsa2026-08/ Mozilla Corporation Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-116 Improper Encoding or Escaping of Output CISA-ADP  
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor CISA-ADP  
CWE-352 Cross-Site Request Forgery (CSRF) CISA-ADP  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

5 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-0818
NVD Published Date:
01/28/2026
NVD Last Modified:
02/04/2026
Source:
Mozilla Corporation