Critical severity · published Aug 19, 2025
CVE-2025-54143
Sandboxed iframes could allow local downloads despite sandbox restrictions
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
Sandboxed iframes on webpages could potentially allow downloads to the device, bypassing the expected sandbox restrictions declared on the parent page. This vulnerability was fixed in Firefox for iOS 141.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 141.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-54143
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-54143
Issue Tracking
https://bugzilla.mozilla.org/show_bug.cgi?id=1912671
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-60/
More from Firefox
10.0
CVE-2019-11708
Mozilla Firefox and Thunderbird Sandbox Escape Vulnerability
9.8
CVE-2024-9680
Mozilla Firefox Use-After-Free Vulnerability
9.8
CVE-2010-3765
Mozilla Multiple Products Remote Code Execution Vulnerability
9.6
CVE-2022-26486
Mozilla Firefox Use-After-Free Vulnerability
8.8
CVE-2023-5217
Google Chromium libvpx Heap Buffer Overflow Vulnerability