How severe is CVE-2026-9939?

CVE-2026-9939 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-9939 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-9939?

CVE-2026-9939 affects Google Chrome. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-9939?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-9939 have an EU (EUVD) identifier?

Yes. CVE-2026-9939 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33081.

When was CVE-2026-9939 published?

CVE-2026-9939 was published on 2026-05-28 and last updated on 2026-06-17.

CVE-2026-9939

CVE-2026-9939 is a high-severity vulnerability in Google Chrome with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-122.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-33081
Weakness: CWE-122
Affected product: Google Chrome
Published: 2026-05-28
Last modified: 2026-06-17

Description

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)

Frequently asked questions

What is 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)
How severe is CVE-2026-9939?: CVE-2026-9939 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-9939 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-9939?: CVE-2026-9939 affects Google Chrome. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-9939?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-9939 have an EU (EUVD) identifier?: Yes. CVE-2026-9939 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33081.
When was CVE-2026-9939 published?: CVE-2026-9939 was published on 2026-05-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*

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