Patchfirst
CVE-2026-109750 Critical · 9.6 EPSS 0.4%

Site isolation issue in the DOM: Web Authentication component

Mozilla · Firefox

Summary

A site isolation flaw in the DOM Web Authentication component of Mozilla Firefox allows content from one site to be handled outside the expected isolation boundary. An remote attacker can exploit it without authentication by getting a user to interact with attacker-controlled content, such as visiting a malicious page.

Official description · NVD

Site isolation issue in the DOM: Web Authentication component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Breakdown
15.4 / 100
Exploited
Not confirmed
Reports
0
Tactics
0/15

Disclosed on 13 Oct 2026. No public exploit code or confirmed exploitation is recorded.

techniques

No techniques linked

No ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.

What security researchers reported

Not named in any threat report yet

Also mentioned in 9 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

3 links, grouped by NVD tag
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