ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-9309

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

Published Jun 1, 2026 · catalog updated Jul 22, 2026 · Firefox for iOS Reader

Check if you run it

No confirmed exploitation is on record for CVE-2026-9309. EPSS is 0.26%. Act only if a listed version of Firefox for iOS Reader is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Firefox for iOS Reader).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.26%
Remediation
Advisory link
Affected products
cpe mozilla/firefox

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe mozilla/firefoxversion unspecified

How to fix CVE-2026-9309

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-9309. EPSS is 0.26%. Act only if a listed version of Firefox for iOS Reader is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-79: Cross-site Scripting (XSS). EPSS 0.26%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 1, 2026 · NIST NVD

    Detected

    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.

  2. Jul 22, 2026 · NIST NVD

    Updated

    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.

Sources

  • CVE.orgVulnerability recordCVE-2026-9309

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-9309

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2026-9309

    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 ar

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.