VulnerabilityPublished 27 Oct 2026

CVE-2026-117965: Mozilla Firefox · Same-origin policy bypass in the Address Bar component

Affects Mozilla FirefoxSource CVE Database V5

Not known to be exploited.

Data as of 27 Oct 2026, 14:58 UTC

Severity

High

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

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Oct 2026
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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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.

What to do

AI-suggested

A fix for this vulnerability is available and has been incorporated into Firefox 159 and Firefox ESR 153.6. Users and administrators should update affected Firefox installations to these versions or later to remediate the issue. No additional mitigation actions are specified or required beyond applying the official update.

Description

CVE-2026-117965 is a same-origin policy bypass vulnerability in the Address Bar component of Mozilla Firefox. This security flaw allows bypassing the browser's same-origin policy, which is a critical security control that restricts how documents or scripts loaded from one origin can interact with resources from another origin. The vulnerability was addressed and fixed in Firefox version 159 and Firefox ESR 153.6.

Impact

The impact of this vulnerability is high because bypassing the same-origin policy can lead to unauthorized access to sensitive information across different web origins, potentially compromising user data confidentiality and integrity. However, there is no indication of active exploitation in the wild at this time.

Summary

This vulnerability involves a bypass of the same-origin policy in the Address Bar component of Firefox. The same-origin policy is fundamental to web security, preventing malicious scripts on one site from accessing data on another. The flaw was identified and fixed by Mozilla in Firefox 159 and Firefox ESR 153.6. The vendor advisory categorizes the impact as high and includes this fix as part of a broader security update addressing multiple high-impact vulnerabilities.

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 27 Oct 2026, 14:58 UTC

Technical details

References

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