What is CVE-2026-8706?

CVE-2026-8706 is a medium-severity vulnerability in Mozilla Firefox, classified under Information Disclosure. CVSS score: 6.5/10. Published 2026-05-19.

How severe is CVE-2026-8706?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Auth bypass in Mozilla Firefox

CVE-2026-8706

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.

Vulnerability class: Information Disclosure

Published 2026-05-19 · last modified 2026-07-23.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (13.3th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 13.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Mozilla Firefox
Mozilla Firefox For iOS — versions 151.0

Weakness classification (CWE)

References

bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
www.mozilla.org/security/advisories/mfsa2026-49/ (Vendor Advisory)

Frequently asked questions

What is CVE-2026-8706?: CVE-2026-8706 is a medium-severity vulnerability in Mozilla Firefox, classified under Information Disclosure. CVSS score: 6.5/10. Published 2026-05-19.
How severe is CVE-2026-8706?: Medium severity. CVSS v3 base score is 6.5 out of 10.