About the compromised eMudhra intermediate CAs

Your Apple devices automatically block the compromised certificates in Safari, Mail, and apps that use Apple's frameworks. To stop command-line tools on Mac from accepting them, update to the latest version of macOS.

Apple devices automatically block the certificates of the compromised eMudhra intermediate Certification Authorities (CAs) that issue TLS certificates. This block works in Safari, Mail, and apps that use Apple's networking and security frameworks.

Some command-line tools included with macOS or the Xcode Command Line Tools (such as curl and git) require an extra step to stop accepting these certificates:

• Update to the latest version of macOS: The latest version of macOS contains the strongest security protections. Starting in macOS 27.2.1, these command-line tools stop accepting these certificates. For Mac computers that use macOS 26 or macOS 15, macOS 26.7.3 and macOS 15.8.3 also include this protection.

• If you can't update your Mac: If you use these command-line tools but can't update your Mac to macOS 27.2.1, 26.7.3, or 15.8.3, you can remove the root CA certificates from /etc/ssl/cert.pem.

Update macOS

What happened

The private keys of eight intermediate CAs operated by eMudhra were compromised. Two of these CAs issue code signing certificates, which Apple's frameworks don't trust. The other six issue TLS certificates. Someone with keys from these six CAs could create certificates that appear valid for any website. eMudhra and Sectigo have revoked the affected certificates.

Each of the 6 TLS intermediate CAs has 2 certificates, for 12 in total:

• A certificate issued by emSign Root TLS CA - G3, which chains to emSign ECC Root CA - G3

• A certificate cross-signed by Sectigo, which chains to AAA Certificate Services

View a list of these 12 certificates

What Apple has done

Apple blocks these 12 certificates and emSign ECC Root CA - G3 in Safari, Mail, and apps that use Apple's networking and security frameworks. Updates to certificate configuration data are sent to devices automatically and as needed, so you don't need to install a software update to get this block.

Starting in macOS 27.2.1, macOS also blocks these 12 certificates in the command-line tools included with macOS or the Xcode Command Line Tools. It also removes the two root CA certificates that the 12 certificates chain to from /etc/ssl/cert.pem, along with three other eMudhra root CA certificates. macOS 26.7.3 and macOS 15.8.3 also include this protection.

View the root CA certificates removed from /etc/ssl/cert.pem

If you can't update your Mac

On Mac, some command-line tools included with macOS or the Xcode Command Line Tools (including curl, git, python3, ruby, perl, and openssl) check certificates against /etc/ssl/cert.pem. For certificates that chain to a root CA certificate in this file, these tools don't check Apple's block or whether the certificate has been revoked.

If you use these tools but can't update your Mac to macOS 27.2.1, macOS 26.7.3, or macOS 15.8.3, you can remove root CA certificates from the file.

• These steps affect every tool that uses /etc/ssl/cert.pem. Afterward, tools that use only this file might not be able to verify some websites whose certificates chain to these root CA certificates through intermediate CAs that weren't affected.

• You need an administrator account, or you can deploy the commands with your device management solution. Copy each command exactly as written. Learn what to do if you get an alert about possible malware when pasting the command into Terminal.

To remove root CA certificates from /etc/ssl/cert.pem:

1. Back up the file. If a backup already exists, this command keeps it:

   • [ -e /etc/ssl/cert.pem.orig ] || sudo cp -p /etc/ssl/cert.pem /etc/ssl/cert.pem.orig

2. Remove emSign ECC Root CA - G3. This command makes a copy of the file without emSign ECC Root CA - G3, checks that the copy isn't empty, and replaces the original. It shows nothing when it succeeds:

   • t=$(mktemp) && awk -v s='=== /C=IN/OU=emSign PKI/O=eMudhra Technologies Limited/CN=emSign ECC Root CA - G3' '/^(===|###) /{skip=0} $0==s{skip=1} !skip' /etc/ssl/cert.pem > "$t" && [ -s "$t" ] && sudo install -m 0644 -o root -g wheel "$t" /etc/ssl/cert.pem; rm -f "$t"

3. Optional: Removing emSign ECC Root CA - G3 doesn't stop these tools from accepting the six certificates that Sectigo cross-signed, because these tools can still verify them through AAA Certificate Services. To stop these tools from accepting those six certificates through the file, you can also remove AAA Certificate Services. This command works the same way as the one in step 2:

   • t=$(mktemp) && awk -v s='=== /C=GB/ST=Greater Manchester/L=Salford/O=Comodo CA Limited/CN=AAA Certificate Services' '/^(===|###) /{skip=0} $0==s{skip=1} !skip' /etc/ssl/cert.pem > "$t" && [ -s "$t" ] && sudo install -m 0644 -o root -g wheel "$t" /etc/ssl/cert.pem; rm -f "$t"

4. Check the result. This command lists either root CA certificate if it's still in the file. If you removed both, it shows nothing. If the command shows an error, restore the backup from step 1.

   • openssl crl2pkcs7 -nocrl -certfile /etc/ssl/cert.pem | openssl pkcs7 -print_certs -noout | grep -E 'emSign ECC Root CA - G3|AAA Certificate Services'

After each software update, run the command in step 4. If it lists a root CA certificate that you removed, repeat these steps.

After you update to macOS 27.2.1, macOS 26.7.3, or macOS 15.8.3, you don't need to repeat these steps. Delete your backup using sudo rm /etc/ssl/cert.pem.orig, and don't restore a backup that you made before the update.

Blocked certificates

Root CA certificates removed from /etc/ssl/cert.pem

macOS 27.2.1, macOS 26.7.3, and macOS 15.8.3 remove these root CA certificates from /etc/ssl/cert.pem. Tools that use only this file might not be able to verify some websites whose certificates chain to these root CA certificates.