What is CVE-2026-87502?

CVE-2026-87502 is a medium-severity vulnerability in Google Chrome, classified under Unintended Proxy or Intermediary (Confused Deputy). CVSS score: 4.2/10. Published 2026-09-09.

How severe is CVE-2026-87502?

Medium severity. CVSS v3 base score is 4.2 out of 10.

Vulnerability in Google Chrome

CVE-2026-87502

Confused deputy in Fullscreen in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process and leveraged social engineering to spoof UI elements via a crafted HTML page. (Chromium security severity: Low)

Published 2026-09-09 · last modified 2026-09-09.

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:L.

EPSS exploit prediction

EPSS: 0.002 (11.4th percentile), scored 2026-10-24.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 11.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Google Chrome

Weakness classification (CWE)

CWE-441 — Unintended Proxy or Intermediary (Confused Deputy)

References

chromereleases.googleblog.com/2026/09/stable-channel-update-for-desktop_0808145… (Release Notes, Vendor Advisory)
issues.chromium.org/issues/515426792 (Permissions Required)

Frequently asked questions

What is CVE-2026-87502?: CVE-2026-87502 is a medium-severity vulnerability in Google Chrome, classified under Unintended Proxy or Intermediary (Confused Deputy). CVSS score: 4.2/10. Published 2026-09-09.
How severe is CVE-2026-87502?: Medium severity. CVSS v3 base score is 4.2 out of 10.