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Fencer Vulns
high 8.8

CVE-2025-9866 json

Inappropriate implementation in Extensions in Google Chrome prior to 140.0.7339.80 allowed a remote attacker to bypass content security pol…

published 2025-09-03 14 mo ago modified 2026-09-26 44 d ago also EUVD-2025-26672

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

Inappropriate implementation in Extensions in Google Chrome prior to 140.0.7339.80 allowed a remote attacker to bypass content security policy via a crafted HTML page. (Chromium security severity: Medium)

Patch / fix

  • google chrome 140.0.7339.80
  • chromium Debian 12 140.0.7339.80-1~deb12u1
  • chromium Debian 13 140.0.7339.80-1~deb13u1
  • chromium Debian 14 140.0.7339.80-1

debian advisories DEBIAN-CVE-2025-9866

  • chromium openSUSE Tumbleweed 140.0.7339.80-1.1

opensuse advisories openSUSE-SU-2025:15524-1

  • qt6-qtwebengine Alpine 3.22 6.8.3-r1
  • qt6-qtwebengine Alpine 3.24, Alpine 3.23 6.9.2-r1

alpine advisories ALPINE-CVE-2025-9866

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-9866 updated cvss 6.5

chromium-browser: Inappropriate implementation in Extensions in Google Chrome

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
14 mo ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Google Chrome

Classification

Weakness
  • CWE-693 Protection Mechanism Failure
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.