Known exploited · Google
CVE-2023-4863: Google Chromium WebP Heap-Based Buffer Overflow Vulnerability
What it is
Google Chromium WebP contains a heap-based buffer overflow vulnerability that allows a remote attacker to perform an out-of-bounds memory write via a crafted HTML page. This vulnerability can affect applications that use the WebP Codec.
- Vendor
- Product
- Chromium WebP
- Added to KEV
- September 13, 2023
- CISA due date
- October 4, 2023
- Ransomware use
- Unknown
- Weakness
- CWE-787: Out-of-bounds Write
What CISA requires
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Forensic triage
No
What to do now
- Find every instance of Chromium WebP you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before October 4, 2023 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
Not sure you are clear?
We check where you run it, patch or mitigate with your team, and look for signs it was already used against you.
Talk to our teamT Academy
Train the engineers who fix it
Security engineering on real hosts in the browser, every objective checked on the machine. The first two lessons of Linux 1 are free.
Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.