Medium 5.4Published Jun 1, 2026

CVE-2026-9309Firefox for iOS Reader View did not properly escape HTML tags in JSON-LD metadata.

Updated under an hour ago (2026-10-19 11:00 UTC)

Does this affect you?

It affects mozilla firefox. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for mozilla firefox

Exploited in the last 30 days

Firefox for iOS Reader View did not properly escape HTML tags in JSON-LD metadata. A malicious page could inject markup that changed Reader View behavior and leaked sensitive URL parameters. These parameters could then be used to access internal pages, potentially resulting in arbitrary JavaScript execution in an internal origin. This vulnerability was fixed in Firefox for iOS 151.2.

CVSS: 5.4 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jul 22, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

mozilla firefox mozilla:firefox	before 151.2	NVD

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2036573permissions-required
https://www.mozilla.org/security/advisories/mfsa2026-53/vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.