VulnerabilityPublished 27 Oct 2026

CVE-2026-117990: Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component

Source GCVE Database

Authoritative record:CVE-2026-117990· High

Not known to be exploited.

Data as of 27 Oct 2026, 22:14 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-6728-4522-53fg

What to do

AI-suggested

A fix for this vulnerability is available and has been incorporated in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6. Users and administrators should update to these or later versions to mitigate the risk. No additional mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-117990 is a high-impact vulnerability in the Graphics: WebRender component of Mozilla Firefox and Thunderbird. It allows sandbox escape due to incorrect boundary conditions. This flaw was addressed and fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

References

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