CVE-2025-8042: Sandboxed iframe could start downloads

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-19 · updated 2026-09-30
Weakness: CWE-732

Description

Firefox for Android allowed a sandboxed iframe without the `allow-downloads` attribute to start downloads. This vulnerability was fixed in Firefox 141.

Affected products

Mozilla Firefox: before 141.0 — fixed in 141.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 141.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1791322
https://www.mozilla.org/security/advisories/mfsa2025-56/

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