Resource exhaustion in Zyxel Ax7501-B0
CVE-2025-6599
An uncontrolled resource consumption vulnerability in the web server of Zyxel DX3301-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could allow an attacker to perform Slowloris‑style denial‑of‑service (DoS) attacks. Such attacks may temporarily block legitimate HTTP requests and partially disrupt access to the web management interface, while other networking services remain unaffected.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.003 (21.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 21.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for… (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-6599?
- CVE-2025-6599 is a medium-severity vulnerability in Zyxel Ax7501-B0, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2025-11-18.
- How severe is CVE-2025-6599?
- Medium severity. CVSS v3 base score is 5.3 out of 10.