AEGLIX vulnerability intelligence
CVE-2023-27992
CRITICAL · CVSS 9.8 · Analyzed
Published: 2023-06-19 · Updated: 2026-06-17 · Source: NVD
Stored catalog record
Source record retrieved 2026-10-28T14:19:32.070739+00:00. Scheduled imports handle updates; this page does not assert that the provider was queried just now.
Vulnerability overview
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.
Patch review priority
Known exploitation: prioritize review
- CISA KEV lists real-world exploitation.
FIRST EPSS: 82.26% · percentile 99.7 · score date 2026-10-27.
EPSS estimates probability of exploitation in the next 30 days. It does not measure your exposure or prove exploitation. The elevated threshold is 10%; CISA KEV takes precedence. About FIRST EPSS ↗
Severity and scoring
- CVSS score
- 9.8 · CRITICAL
- CVSS version
- 3.1
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-78
CVSS measures technical severity; it does not establish whether this vulnerability is being exploited in your environment.
Known exploitation and remediation
Listed in CISA’s Known Exploited Vulnerabilities catalog.
- Affected product
- Zyxel · Multiple Network-Attached Storage (NAS) Devices
- Added to catalog
- 2023-06-23
- Required action
- Apply updates per vendor instructions.
- CISA remediation due date
- 2023-07-14
CISA deadlines apply to the organizations covered by its directives. Confirm your own remediation requirements.
Verify affected versions and patch availability in the vendor advisory before making changes.
Affected products and versions
cpe:2.3:o:zyxel:nas326_firmware:*:*:*:*:*:*:*:*
Before (exclusive): 5.21\(aazf.14\)c0
cpe:2.3:o:zyxel:nas540_firmware:*:*:*:*:*:*:*:*
Before (exclusive): 5.21\(aatb.11\)c0
cpe:2.3:o:zyxel:nas542_firmware:*:*:*:*:*:*:*:*
Before (exclusive): 5.21\(abag.11\)c0
These are NVD CPE applicability entries. Some products depend on configuration conditions; consult the official record to confirm applicability.
Advisories and references
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products
Patch · Vendor Advisory
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products
Patch · Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27992
US Government Resource