VulnerabilityPublished 10 Nov 2026

CVE-2026-124913: Site Isolation Issue

Source GCVE Database

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Authoritative record:CVE-2026-124913· High

Not known to be exploited.

Data as of 10 Nov 2026, 17:33 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 10 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-x4pr-hxfp-r2wx

What to do

AI-suggested

Users should update to Firefox 160 or later, or Firefox ESR 153.7 or later, where this vulnerability has been fixed. Applying these official updates fully mitigates the issue.

Description

CVE-2026-124913 is a site isolation vulnerability in the Networking component of Firefox. This issue was addressed and fixed in Firefox 160 and Firefox ESR 153.7. The vulnerability is considered high impact by the vendor. No known exploits in the wild have been reported.

Impact

The vulnerability is rated as high impact by Mozilla, indicating it could allow significant security breaches related to site isolation in the Networking component. However, there are no reports of active exploitation in the wild at this time.

Summary

This vulnerability involves a site isolation issue within the Networking component of Firefox. Site isolation is a security feature designed to separate different web origins into different processes to prevent data leakage or unauthorized access. The flaw could potentially undermine this isolation, leading to security risks. Mozilla fixed this vulnerability in Firefox 160 and Firefox ESR 153.7 as part of a security update addressing multiple high-impact issues.

References

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