CVE-2025-10859: Mozilla Firefox for iOS · Vulnerability
Affects Mozilla Firefox for iOSSource CVE Database V5
Not known to be exploited · CVSS 4.0 Medium : upgrade to 143.1 when convenient.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 143.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade Mozilla Firefox for iOS to 143.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox for iOS | Affected
| Fixed in
|
AI-suggested
Users should update to Firefox for iOS version 143.1 or later, where this vulnerability has been fixed. Applying this official patch fully mitigates the issue. No additional mitigation steps are required beyond updating to the fixed version.
Description
Cookie storage for non-HTML temporary documents was being shared incorrectly with normal browsing content, allowing information from private tabs to escape Incognito mode even after the user closed all tabs. This vulnerability was fixed in Firefox for iOS 143.1.