Chrome is a widely used browser; a V8 type‑confusion RCE can enable arbitrary code execution in user contexts across organizations and warrants broad IT notice and patching.
CVE-2026-121221
Type‑confusion RCE in Chrome V8 prior to 157.0.8103.38.
Is CVE-2026-121221 being exploited?
Not confirmed. CVE-2026-121221 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-121221?
CVE-2026-121221 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-121221?
Yes. A fix has been recorded for CVE-2026-121221. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-121221 affect?
CVE-2026-121221 affects Google Chrome < 157.0.8103.38, Chrome V8 engine. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-121221?
Update Chrome to 157.0.8103.38+ immediately and ensure auto‑update policies.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via crafted HTML that executes inside Chrome's V8 sandbox, enabling attackers to run arbitrary code within the browser process.
Immediate action required
- affected< 157.0.8103.38
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
cisa ssvc
- exploitation
- none
- automatable
- no
- technical impact
- total
Assessed by CISA 4 Nov 2026 (SSVC 2.0.3).
timeline
- 3 Nov 2026Published
- 4 Nov 2026CISA SSVC assessment: exploitation none · same day later
- 5 Nov 2026CVE record last updated · 1 day later
- 5 Nov 2026Analysed by vulneraibility.com · same day later
- Linkchromereleases.googleblog.com /2026/11/stable-channel-update-for-desktop.html
- Linkissues.chromium.org /issues/578688670
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.