Vulnerability record

CVE-2023-33009

A permanent, source-backed tracker page. Values are shown only when returned; explicit gaps and read failures remain different states.

Full record read. Reported values and explicit gaps below come from the tracked record. Tracker snapshot: Aug 8, 2026.

What it is

Reported

Zyxel ATP, USG FLEX, USG FLEX 50(W), USG20(W)-VPN, VPN, and ZyWALL/USG firewalls contain a buffer overflow vulnerability in the notification function that could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and remote code execution on an affected device. Source description excerpt; complete tracked detail loads below.

NVD published: May 24, 2023 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

What is affected

Reported

Zyxel — Multiple Firewalls. Product-level identification only; no affected-version conclusion is available from this field.

NVD published: May 24, 2023 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Urgency and basis

Reported

Act · 465.4

Tracker decision tier from the evidence detailed below · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Exploitation evidence

Reported

kev-listed · CISA KEV · VulnCheck KEV · ENISA exploited-vulnerability catalog

Active since: Jun 5, 2023 · CISA KEV added: Jun 5, 2023 · VulnCheck KEV added: Jun 5, 2023 · ENISA added: Jun 5, 2023 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

What to do

Reported

Apply updates per vendor instructions.

Source remediation ↗

Tracked source remediation field · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Evidence detail

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