Threats / Google / CVE-2023-4863
CVE-2023-4863
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Google Chromium WebP vulnerability
Google Chromium WebP contains a heap-based buffer overflow (CWE-787) allowing remote code execution through crafted HTML. Active exploitation observed in the wild.
Verdict
Today item — known-exploited.
A remote attacker can trigger out-of-bounds memory writes in WebP processing, potentially achieving code execution on systems running affected Chromium versions. High EPSS score and confirmed wild exploitation indicate immediate risk.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
9 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-09-13).
Probability (EPSS)
EPSS 0.99739 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Google, Chromium WebP. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-787 Out-of-bounds Write — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious HTML page containing a specially-formed WebP image that triggers a heap buffer overflow during decoding.
Business
Users visiting attacker-controlled or compromised websites face arbitrary code execution in the browser context.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I deliver the malicious HTML via email, social engineering, or ad networks to reach target systems.
Business
Widespread exposure across consumer and enterprise user bases increases incident response burden and potential data breach scope.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute arbitrary code with browser privileges to steal credentials, install malware, or pivot to system resources.
Business
Compromised endpoints enable lateral movement, data exfiltration, and persistent infrastructure compromise.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05