VulnerabilityPublished 27 Oct 2026

CVE-2026-118023: Sandbox Escape Due to Use-after-free

Source GCVE Database

Authoritative record:CVE-2026-118023· High

Not known to be exploited.

Data as of 27 Oct 2026, 16:44 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.

ghsa-2fvm-8qcx-rf42

What to do

AI-suggested

This vulnerability has been fixed in Firefox version 159. Users and administrators should update to Firefox 159 or later to remediate this issue. No additional mitigation steps are required beyond applying the official update.

Description

CVE-2026-118023 is a use-after-free vulnerability in the Graphics: WebRender component of Firefox that allows sandbox escape. This vulnerability was fixed in Firefox version 159. The issue could enable an attacker to break out of the browser's sandbox environment, potentially leading to elevated privileges or code execution outside the intended security boundaries.

Impact

Successful exploitation of this use-after-free vulnerability could allow an attacker to escape the sandbox environment of Firefox, potentially leading to privilege escalation or arbitrary code execution outside the browser's restricted context. This poses a high security risk to users running affected versions of Firefox prior to 159.

Summary

This vulnerability involves a use-after-free flaw in the Graphics: WebRender component of Firefox. Exploitation of this flaw could allow an attacker to escape the browser sandbox, bypassing security restrictions. The vulnerability was addressed and fixed in Firefox 159 as part of a broader set of high-impact security fixes released by Mozilla on October 27, 2026.

References

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