CVE-2026-9986

Insufficient validation of untrusted input in OptimizationGuide in Google Chrome prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to perform UI spoofing via a crafted HTML page. (Chromium security severity: High)

Published: 2026-05-28 Last update: 2026-05-29 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-9986 is rated Low Risk (24.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.07%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-9986

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-30 0.05% 0.07% +0.03%
2 2026-05-29 — 0.05% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-9986

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.2 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.6 2.5 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-9986

GitHub Security Advisory for CVE-2026-9986

GHSA-g8q5-42mc-pjxg · Severity: medium — Insufficient validation of untrusted input in OptimizationGuide in Google Chrome prior to 148.0...

OS Trackers for CVE-2026-9986

vendor priority summary link
debian end-of-life CVE-2026-9986 end-of-life priority: Debian including 1 source packages (chromium), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-9986
redhat high — https://access.redhat.com/security/cve/CVE-2026-9986

Affected software / configurations for CVE-2026-9986

Vendor Product Version Raw CPE
google chrome < 148.0.7778.216 cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*
google chrome < 148.0.7778.215 cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*

References for CVE-2026-9986

cvelogic Threat Intelligence