Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N N U H H H 9.8 .8283 99.7 YES
AFFECTED Product Versions Fixed NAS326 firmware < V5.21(AAZF.14)C0 – — NAS540 firmware < V5.21(AATB.11)C0 – — NAS542 firmware < V5.21(ABAG.11)C0 – —
TIMELINE Mar 9 Reserved by Zyxel Jun 19 Published (CNA: Zyxel) Jun 23 Added to CISA KEV, remediation due 2023-07-14
The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.
| Date | Event | Detail |
|---|---|---|
| March 9, 2023 | Reserved | Reserved by Zyxel |
| June 19, 2023 | Published | Published (CNA: Zyxel) |
| June 23, 2023 | KEV ADDED | Added to CISA KEV, remediation due 2023-07-14 |
Authoritative record: CVE-2023-27992 at cve.org
Vendors: zyxel
Weaknesses: CWE-78
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2023-27992 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
