CVE-2026-8706: Sensitive user data could be leaked to other applications through Reader mode

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-19 · updated 2026-07-23
Weakness: CWE-200

Description

Firefox for iOS hosted Reader mode on an unauthenticated local web server, allowing another application on the same device to request arbitrary URLs and receive the response rendered with the signed-in user's cookies. This vulnerability was fixed in Firefox for iOS 151.0.

Affected products

Mozilla Firefox: before 151.0 — fixed in 151.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 151.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2036618
https://www.mozilla.org/security/advisories/mfsa2026-49/

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