CVE-2025-9866
published 2025-09-03CVE-2025-9866: 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…
PriorityP346high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.35%
27.6th percentile
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)
Affected
9 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| chromium | chromium | >= 0 < 140.0.7339.80-1~deb12u1 | 140.0.7339.80-1~deb12u1 |
| chromium | chromium | >= 0 < 140.0.7339.80-1~deb13u1 | 140.0.7339.80-1~deb13u1 |
| chromium | chromium | >= 0 < 140.0.7339.80-1 | 140.0.7339.80-1 |
| debian | chromium | < chromium 140.0.7339.80-1~deb12u1 (bookworm) | chromium 140.0.7339.80-1~deb12u1 (bookworm) |
| chrome | < 140.0.7339.80 | 140.0.7339.80 | |
| chrome | >= 140.0.7339.80 < 140.0.7339.80 | 140.0.7339.80 | |
| chrome_chrome | — | — | |
| msrc | microsoft_edge | — | — |
| paloalto | prisma_browser | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
osv8.8HIGH
vendor_debian8.8HIGH
vendor_msrc8.8HIGH
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OSV
CVE-2025-9866: Inappropriate implementation in Extensions in Google Chrome prior to 140
osv·2025-09-03·CVSS 8.8
CVE-2025-9866 [HIGH] CVE-2025-9866: Inappropriate implementation in Extensions in Google Chrome prior to 140
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)
Palo Alto
PAN-SA-2025-0016 Chromium: Monthly Vulnerability Update (October 2025)
vendor_paloalto·2025-10-08·CVSS 8.8
CVE-2025-9132 [HIGH] PAN-SA-2025-0016 Chromium: Monthly Vulnerability Update (October 2025)
PAN-SA-2025-0016 Chromium: Monthly Vulnerability Update (October 2025)
Palo Alto Networks incorporated the following Chromium security fixes into our products: https://chromereleases.googleblog.com/2025/09/stable-channel-update-for-desktop_23.html https://chromereleases.googleblog.com/2025/09/stable-channel-update-for-desktop_17.html https://chromereleases.googleblog.com/2025/09/stable-channel-update-for-desktop_9.html CVE Summary CVE-2025-9132 Out of bounds write in V8 CVE-2025-9478 Use after free in ANGLE CVE-2025-9864 Use after free in V8 CVE-2025-9865 Inappropriate implementation in Toolbar CVE-2025-9866 Inappropriate implementation in Extensions CVE-2025-9867 Inappropriate implementation in Downloads CVE-2025-10200 Use after free in Serviceworker CVE-2025-10201 Inappropriate implemen
Microsoft
Chromium: CVE-2025-9866 Inappropriate implementation in Extensions
vendor_msrc·2025-09-09·CVSS 8.8
CVE-2025-9866 [HIGH] Chromium: CVE-2025-9866 Inappropriate implementation in Extensions
Chromium: CVE-2025-9866 Inappropriate implementation in Extensions
Description: This CVE was assigned by Chrome. Microsoft Edge (Chromium-based) ingests Chromium, which addresses this vulnerability. Please see Google Chrome Releases for more information.
FAQ: Why is this Chrome CVE included in the Security Update Guide?
The vulnerability assigned to this CVE is in Chromium Open Source Software (OSS) which is consumed by Microsoft Edge (Chromium-based). It is being documented in the Security Update Guide to announce that the latest version of Microsoft Edge (Chromium-based) is no longer vulnerable.
How can I see the version of the browser?
In your Microsoft Edge browser, click on the 3 dots (...) on the very right-hand side of the window
Click on Help and Feedback
Click on About Microsof
Chrome
Stable Channel Update for Desktop: CVE-2025-9865
vendor_chrome·2025-09-02·CVSS 5.4
CVE-2025-9865 [MEDIUM] Stable Channel Update for Desktop: CVE-2025-9865
Stable Channel Update for Desktop
CVE-2025-9865: Inappropriate implementation in Toolbar. Reported by Khalil Zhani on 2025-08-07 [$4000][ 379337758 ] Medium CVE-2025-9866: Inappropriate implementation in Extensions
Reported by NDevTK on 2024-11-16 [$1000][ 415496161 ] Medium CVE-2025-9867: Inappropriate implementation in Downloads
Severity: medium
Debian
CVE-2025-9866: chromium - Inappropriate implementation in Extensions in Google Chrome prior to 140.0.7339....
vendor_debian·2025·CVSS 8.8
CVE-2025-9866 [HIGH] CVE-2025-9866: chromium - Inappropriate implementation in Extensions in Google Chrome prior to 140.0.7339....
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)
Scope: local
bookworm: resolved (fixed in 140.0.7339.80-1~deb12u1)
bullseye: open
forky: resolved (fixed in 140.0.7339.80-1)
sid: resolved (fixed in 140.0.7339.80-1)
trixie: resolved (fixed in 140.0.7339.80-1~deb13u1)
No detection rules found.
No public exploits indexed.
2025-09-03
Published