CVE-2023-4863
Google Chromium WebP Heap-Based Buffer Overflow Vulnerability
Google Chromium WebP
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)
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 13 September 2023. US federal agencies were required to remediate it by 4 October 2023.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 100%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2023-4863 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2023-4863.
What does CVE-2023-4863 affect?
CVE-2023-4863 affects Google Chromium WebP. 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)
How severe is CVE-2023-4863?
CVE-2023-4863 is rated HIGH with a CVSS base score of 8.8. EPSS puts the probability of exploitation in the next 30 days at 100%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 4 October 2023.
How should organisations respond to CVE-2023-4863?
Apply the vendor patch for Google Chromium WebP as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.