VulnerabilityPublished 10 Nov 2026

CVE-2026-124931: Same-origin Policy Bypass

Source GCVE Database

Compare

Authoritative record:CVE-2026-124931· 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-63m2-4pqf-357p

What to do

AI-suggested

A fix for this vulnerability is available and has been incorporated into Firefox 160 and Firefox ESR 153.7. Users and administrators should update affected Firefox installations to these versions or later to remediate the issue. There are no indications that additional mitigation steps are required beyond applying the official update.

Description

CVE-2026-124931 is a same-origin policy bypass vulnerability in the DOM Core and HTML components of Firefox. This security flaw was addressed and fixed in Firefox version 160 and Firefox ESR 153.7. The vulnerability could allow an attacker to bypass browser security restrictions that normally isolate content from different origins.

Impact

The impact is classified as high by the vendor. A same-origin policy bypass can allow malicious web content to access or manipulate data from other origins, potentially leading to unauthorized data exposure or manipulation within the browser context.

Summary

This vulnerability involves a bypass of the same-origin policy within the DOM Core and HTML components of Firefox. The same-origin policy is a critical security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. The flaw was fixed in Firefox 160 and Firefox ESR 153.7, as documented in the Mozilla Foundation Security Advisory 2026-125. No public exploits or in-the-wild exploitation have been reported for this issue.

References

Community reviews

Loading reviews…