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Threats / Google / CVE-2023-5217
CVE-2023-5217 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Google Chromium libvpx vulnerability

Heap buffer overflow in Chromium libvpx VP8 encoding allows remote code execution via crafted HTML, affecting Chrome and other browsers using the library.

Verdict

Today item — known-exploited.

A remote attacker can trigger heap corruption through a malicious webpage, potentially achieving code execution in the context of the affected browser process. Active exploitation in the wild confirms practical threat.

CISA KEV Yes · 2023-10-023EPSS 0.34401 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit 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
8 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 2023-10-02).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.34401 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Google, Chromium libvpx. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
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.
NVD ↗Reported
WeaknessCWE-787 · Out-of-bounds WriteMemory safety
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution 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 board
1

Front door — unauthenticated access narrative 1

Attacker
Craft a malicious HTML page with specially formatted VP8 video data to trigger the heap buffer overflow during encoding.
Business
User visits attacker-controlled or compromised website and browser process is compromised, risking data theft and system access.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
Achieve code execution within the browser sandbox by overwriting heap memory structures during VP8 processing.
Business
Attacker gains ability to steal credentials, session tokens, and sensitive user data accessible to the browser context.
3

Lateral reach — past segmentation narrative 3

Attacker
Escape browser sandbox through heap corruption to gain elevated privileges on the host system.
Business
Full system compromise becomes possible, enabling installation of malware, ransomware, or persistent backdoors.
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

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Public PoC available (VulnCheck)
  • 8 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by Chrome (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by ChromeCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.