CVE-2026-9939

Heap buffer overflow in WebCodecs in Google Chrome prior to 148.0.7778.216 allowed a remote attacker to execute arbitrary code inside a sandbox 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-2026-9939 is rated Moderate Risk (43.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.07%). Review affected assets and schedule remediation.

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-2026-9939

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 0.03% 0.07% +0.04%
2 2026-05-29 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-9939

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-9939

GitHub Security Advisory for CVE-2026-9939

GHSA-c7jh-hgv7-r6m2 · Severity: high — Heap buffer overflow in WebCodecs in Google Chrome prior to 148.0.7778.216 allowed a remote...

OS Trackers for CVE-2026-9939

vendor priority summary link
debian end-of-life CVE-2026-9939 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-2026-9939
redhat high — https://access.redhat.com/security/cve/CVE-2026-9939

Affected software / configurations for CVE-2026-9939

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-2026-9939

cvelogic Threat Intelligence