Apple blocks compromised eMudhra certificates in Safari and Mail; some Mac command-line tools still affected

Apple has blocked a set of compromised web certificates issued by the Indian certificate authority eMudhra, according to an Apple support document. The company says the block has been in force since October 19, 2026.

The problem came to light earlier this month, when a security researcher found that the private cryptographic keys behind eight intermediate certificates from eMudhra were weak. Ars Technica first reported the discovery. In principle, weak keys could let an attacker produce certificates that browsers would accept for websites the attacker does not control. MacRumors notes there is currently no evidence that the keys were exploited maliciously.

Apple says the block applies in Safari, Mail and apps that rely on its networking and security frameworks. It takes effect automatically and does not require a software update, so most people do not need to do anything.

There is one caveat for Mac administrators and developers. According to Apple, some command-line tools on macOS can still accept the affected certificates until a future macOS update arrives. In the meantime, Apple says users of those tools can remove the relevant root certificates from the /etc/ssl/cert.pem file by hand. Apple has not said when the update that changes this file by default will ship, and the reports do not name specific macOS versions.

eMudhra's certificates were trusted by several major browsers, including Safari, Chrome, Edge and Firefox. The reports reviewed here do not describe what other browser makers have done in response, so readers who use those browsers may want to check each vendor's own security notices.

For everyday Safari and Mail users, the practical effect is limited: the protection is already active. For anyone who scripts against web services from Terminal or runs command-line utilities that fetch data over HTTPS, Apple's guidance is to review the certificate store until the system-level fix is released.

Apple's full technical details are published in its support document, and the original researcher findings are covered in the Ars Technica report linked below.