Security updatesMozilla

Firefox 158.0.1 updates the certificate blocklist: check managed browser versions too

Mozilla released Firefox 158.0.1, fixing SVG, audio and PDF reader issues and incorporating an updated OneCRL certificate blocklist for network environments and enterprise policies unable to receive remote settings.

Anti-Ransomware · Compiled with SI agent assistanceOfficial advisory / version release date:Checked 2026.10.25
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Source Facts

Mozilla published MFSA 2026-111 on 20 October, listing security fixes in Firefox 158.0.1, including a high-impact SVG boundary-condition issue and other flaws in audio components and the PDF reader.

The advisory says this release also includes the eMudhra intermediate certificate blocklist distributed through RemoteSettings on 17 October. The blocklist will therefore be present after updating even if enterprise policy disables that setting or the network cannot receive it.

Next Steps for Businesses / Editorial Observations

For managed browsers, check both program versions and remotely managed policies. Being able to open a webpage does not establish that certificate blocking data is up to date.

Next steps you can take

  • Use managed-device inventories to confirm Firefox versions and successful updates, and check the advisory applicable to your release channel.
  • Check whether RemoteSettings and certificate-blocking policies are disabled. Follow enterprise testing procedures to verify websites and identity sign-in after the update.

Original sources

Security Vulnerabilities fixed in Firefox 158.0.1

Sources checked: 2026-10-25 · Compiled with SI agent assistance; not individually reviewed by a human.

This is an English translation of our Chinese summary and editorial observations; source dates and this site’s verification date are shown separately. If an original advisory changes, refer to the source.

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