CVE-2026-86853Repeated external URL scheme launches could potentially cause a denial of service in Firefox for iOS
Updated under an hour ago ()
Does this affect you?
It affects Mozilla Firefox for iOS and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
A malicious webpage could repeatedly trigger external URL schemes, causing system prompts or external application launches. This could make Firefox for iOS temporarily unusable until the page is closed. This vulnerability was fixed in Firefox for iOS 155.1.
- CVSS
- 4.3 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- Weakness (CWE)
- CWE-451
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mozilla
- NVD analysis
- Analyzed
- Record last updated
- Sep 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Mozilla Firefox for iOS mozilla:firefox_for_ios (from the name) | from 155.1 not affected | CNA record |
mozilla firefox_mobile mozilla:firefox_mobile | before 155.1 | NVD |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1847631permissions-required
- https://www.mozilla.org/security/advisories/mfsa2026-89/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.