CVE-2025-6599

7.5 high SSVC exploitation: none Analyzed

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.

Fix

Patch, vendor advisory and mitigation references on NVD 1

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-uncontrolled-resource-consumption-and-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-security-routers-and-wireless-extenders-11-18-2025 Vendor Advisory

Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.

Change history 1

2026-10-19 17:16First seenCVSS 7.5 · zyxelNVD modified 2026-10-18 20:10

Affected (CPE criteria) 66

cpe:2.3:o:zyxel:lte3301-plus_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nr5103_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nr5103e_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nr5309_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nr7302_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nr7303_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nebula_fwa505_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nebula_fwa510_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nebula_fwa515_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:nebula_fwa710_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dm4200-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dx3300-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dx3300-t1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dx3301-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dx4510-b1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dx5401-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dx5401-b1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ee3301-00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ee5301-00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ee6510-10_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3300-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3300-t1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3301-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3500-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3501-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3600-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5401-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5401-b1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5501-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5510-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5512-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5601-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5601-t1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex7501-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex7710-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:emg3525-t50b_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:emg5523-t50b_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:emg5723-t50k_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:emg6726-b10a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:gm4100-b0_firmware:*:*:*:*:*:*:*:*
and 26 more

References 1

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-uncontrolled-resource-consumption-and-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-security-routers-and-wireless-extenders-11-18-2025 Vendor Advisory