CVE-2026-85046: Google Chromium V8

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

Yes, if you run Google Chromium V8. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-09-04, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-09-18; treat that as the outer limit, not the target.
EPSS 48.9%, percentile 99: FIRST’s model estimates a 48.9% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
Editorial verdict: Check exposure. Chrome V8 Zero-Days CVE-2026-85046 and CVE-2026-87491 — Both were exploited zero-days, but Chrome and Edge fixed them in early September and auto-update has had six weeks to deliver the fix; the job now is finding browsers that did not update, not a scramble.

What it is

Type confusion in V8 in Google Chrome prior to 152.0.7977.82 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)

CISA’s summary

Google Chromium V8 contains a type confusion vulnerability that allows a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.

Weakness type: CWE-843.

Product: Google Chromium V8 · Assigned by: Chrome · Published: 2026-09-03

Affected and fixed versions

Vendor	Product	Affected versions (per CVE record)
Google	Chrome	152.0.7977.82 < 152.0.7977.82

Severity scores

Scored by	CVSS	Score	Vector
CISA-ADP	3.1	8.8 High	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`

Attack vector: network (remotely reachable)
Attack complexity: low
Privileges required: none (no login)
User interaction: required (a user must click/open something)
Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

CISA KEV: added 2026-09-04; federal due date 2026-09-18. Known ransomware use: Unknown.
CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA SSVC assessment: exploitation active, automatable no, technical impact total.
FIRST EPSS (model of 2026-10-21): 48.88% probability of exploitation activity in the next 30 days; percentile 99.

Timeline

2026-09-03 — CVE record published by Chrome
2026-09-03 — erroneo.us brief: Chrome V8 Zero-Days CVE-2026-85046 and CVE-2026-87491
2026-09-04 — Added to CISA’s Known Exploited Vulnerabilities catalog
2026-09-18 — CISA remediation deadline for US federal agencies
2026-09-21 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Other references from the CVE record and advisory

issues.chromium.org issues.chromium.org
serotav.github.io serotav.github.io
github.com github.com
github.com github.com
news.ycombinator.com news.ycombinator.com

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