What the advisory covers
Mozilla said on November 9 that Firefox 160 for iOS fixes three security issues. It rated two privilege-escalation vulnerabilities high impact. One, CVE-2026-121842, affects the browser’s Reader View component. Mozilla identified a second privilege flaw as CVE-2026-121843 and rated a third issue, CVE-2026-121841, moderate.
The advisory is specific to Firefox for iOS. It gives limited detail about the conditions needed to trigger the flaws and does not state whether Mozilla has observed exploitation. It also gives no version-by-version list of affected older builds. CGH reviewed the advisory and release records and did not test the vulnerabilities.
Check the installed app version
The U.S. App Store listing showed version 160.0 as a free update when CGH checked. Mozilla published the source release earlier, on November 6. A source tag and a store update can appear at different times, so the version installed on the device is the useful check. If an iPhone or iPad still shows an earlier Firefox version, look for the update in the App Store even if automatic updates are on.
For teams that manage Apple devices, the advisory gives a clear version to verify in app inventory. An iOS operating-system update alone does not establish that the Firefox app has updated. CGH did not check availability in every storefront.