Cyber ·
Oss-sec discussion on S/MIME and the NSS/Thunderbird certificate store
On 22 October 2026, a discussion on the oss-sec list proposed investigating which email applications use the NSS/Thunderbird certificate store as a trust anchor for S/MIME and whether they correctly validate X.509 chains.
Source: a comment posted to the oss-sec mailing list on 22 October 2026, under the subject Re: Comodo AAA Services Root and S/MIME. The text is an automatic translation of the feed content. Its scope is narrow and technical: it proposes investigating email applications that use the NSS/Thunderbird certificate store to verify S/MIME messages, and how those applications validate X.509 certificate chains.
The quoted text says that one participant has limited interest in the topic and probably will not investigate it in depth. Instead of conclusions, the comment offers questions as a starting point: are there other email applications that use the NSS/Thunderbird store as a trust anchor for S/MIME, and do they correctly verify X.509 chains? The available excerpt contains no results, tests, affected versions or recommendations. The title mentions a root certification authority, but the text does not describe its status or any impact.
To consult and verify, open the public oss-sec archive for the fourth quarter of 2026 and locate message number 332, using the origin link in the feed itself. Confirm the date, the original author and the full thread, including later replies, before citing any conclusion.