CVE-2026-9078: Firefox iOS RTL Domain Rendering Issue in Link Preview

Severity: medium (CVSS 5.4 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: 2026-05-25 · updated 2026-07-23
Weakness: CWE-451

Description

Firefox for iOS displayed specially crafted right-to-left (RTL) and internationalized domain names (IDNs) incorrectly in link preview UI surfaces. A crafted RTL hostname could visually reorder portions of the displayed domain, causing attacker-controlled sites to appear as trusted origins. This vulnerability was fixed in Firefox for iOS 151.1.

Affected products

Mozilla Firefox: before 151.1 — fixed in 151.1

How to fix

Upgrade to a fixed version: Mozilla Firefox 151.1. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2029371
https://www.mozilla.org/security/advisories/mfsa2026-52/

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