CVE-2023-4863

Google Chromium WebP Heap-Based Buffer Overflow Vulnerability

High 8.8
Exploited: added to CISA KEV 13 Sep 2023

Description

Heap buffer overflow in libwebp in Google Chrome prior to 116.0.5845.187 and libwebp 1.3.2 allowed a remote attacker to perform an out of bounds memory write via a crafted HTML page. (Chromium security severity: Critical)

Key facts

Published: 12 Sep 2023
Last changed: 21 Oct 2025
Assigned by: Chrome
KEV added: 13 Sep 2023
KEV fix due: 4 Oct 2023
EPSS: 99.979% likely to be exploited in the next 30 days, higher than 99.98% of CVEs (scores for 15 Nov 2026)
SSVC (CISA): Exploitation: active; Automatable: no; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

8.8CVSS 3.1, Highfrom CISA (ADP container)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

What to do

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Vendor	Product	Versions
Google	Chrome	116.0.5845.187 up to but excluding 116.0.5845.187 (affected)
Google	libwebp	1.3.2 up to but excluding 1.3.2 (affected)

Timeline

12 Sep 2023 Published
13 Sep 2023 CVE-2023-4863 added to CISA KEV
13 Sep 2023 Added to the CISA KEV catalogue

Weakness

CWE-787