CVE-2025-6599: High severity Zyxel DX3301-T0 vulnerability

Published Nov 18, 2025
·
Updated

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.

Affected Software

137 affected components
Zyxel DX3301-T0<5.50(ABVY.6.3)C0
All of the following
Zyxel Lte3301-plus Firmware<=1.00\(abqu.7\)c0
Zyxel Lte3301-plus
All of the following
Zyxel Nr5103 Firmware<=4.19\(abyc.8\)c0
Zyxel Nr5103
All of the following
Zyxel Nr5103e Firmware<=1.00\(acdj.1\)c0
Zyxel Nr5103e
All of the following
Zyxel Nr5309 Firmware<=1.00\(ackp.1\)b3
Zyxel Nr5309
All of the following
Zyxel Nr7302 Firmware<=5.00\(acha.5\)c0
Zyxel Nr7302
All of the following
Zyxel Nr7303 Firmware<=1.00\(acei.1\)c0
Zyxel Nr7303
All of the following
Zyxel Nebula Fwa505 Firmware<=1.19\(acko.0\)c0
Zyxel Nebula Fwa505
All of the following
Zyxel Nebula Fwa510 Firmware<=1.20\(acgd.1\)c0
Zyxel Nebula Fwa510
All of the following
Zyxel Nebula Fwa515 Firmware<=1.50\(acpz.0\)c0
Zyxel Nebula Fwa515
All of the following
Zyxel Nebula Fwa710 Firmware<=1.20\(acgc.0\)c0
Zyxel Nebula Fwa710
All of the following
Zyxel Dm4200-b0 Firmware<=5.17\(acbs.1.3\)c0
Zyxel Dm4200-b0
All of the following
Zyxel DX3300-T0 firmware<=5.50\(abvy.6.3\)c0
Zyxel DX3300-T0
All of the following
Zyxel Dx3300-t1 Firmware<=5.50\(abvy.6.3\)c0
Zyxel Dx3300-t1
All of the following
Zyxel DX3301-T0 firmware<=5.50\(abvy.6.3\)c0
Zyxel DX3301-T0
All of the following
Zyxel Dx4510-b1 Firmware<=5.17\(abyl.9\)c0
Zyxel Dx4510-b1
All of the following
Zyxel DX5401-B0 firmware<=5.17\(abyo.7\)b2
Zyxel DX5401-B0
All of the following
Zyxel Dx5401-b1 Firmware<=5.17\(abyo.7\)b2
Zyxel Dx5401-b1
All of the following
Zyxel Ee3301-00 Firmware<=5.63\(acmu.1.1\)c0
Zyxel Ee3301-00
All of the following
Zyxel Ee5301-00 Firmware<=5.63\(acld.1.1\)c0
Zyxel Ee5301-00
All of the following
Zyxel Ee6510-10 Firmware<=5.19\(acjq.3\)c0
Zyxel Ee6510-10
All of the following
Zyxel Ex3300-t0 Firmware<=5.50\(abvy.6.3\)c0
Zyxel Ex3300-t0
All of the following
Zyxel Ex3300-t0 Firmware<=5.50\(acdi.2.1\)c0
Zyxel Ex3300-t0
All of the following
Zyxel Ex3300-t1 Firmware<=5.50\(abvy.6.3\)c0
Zyxel Ex3300-t1
All of the following
Zyxel EX3301-T0 firmware<=5.50\(abvy.6.3\)c0
Zyxel EX3301-T0
All of the following
Zyxel Ex3500-t0 Firmware<=5.44\(achr.4\)c0
Zyxel Ex3500-t0
All of the following
Zyxel Ex3501-t0 Firmware<=5.44\(achr.4\)c0
Zyxel Ex3501-t0
All of the following
Zyxel Ex3600-t0 Firmware<=5.70\(acif.1.2\)c0
Zyxel Ex3600-t0
All of the following
Zyxel Ex5401-b0 Firmware<=5.17\(abyo.7\)b2
Zyxel Ex5401-b0
All of the following
Zyxel Ex5401-b1 Firmware<=5.17\(abyo.7\)b2
Zyxel Ex5401-b1
All of the following
Zyxel Ex5501-b0 Firmware<=5.17\(abry.5.5\)c0
Zyxel Ex5501-b0
All of the following
Zyxel Ex5510-b0 Firmware<=5.17\(abqx.10\)c0
Zyxel Ex5510-b0
All of the following
Zyxel Ex5512-t0 Firmware<=5.70\(aceg.5\)c0
Zyxel Ex5512-t0
All of the following
Zyxel Ex5601-t0 Firmware<=5.70\(acdz.4.1\)c0
Zyxel Ex5601-t0
All of the following
Zyxel EX5601-T1 firmware<=5.70\(acdz.4.1\)c0
Zyxel EX5601-T1
All of the following
Zyxel Ex7501-b0 Firmware<=5.18\(achn.2.1\)c0
Zyxel Ex7501-b0
All of the following
Zyxel Ex7710-b0 Firmware<=5.18\(acak.1.4\)c0
Zyxel Ex7710-b0
All of the following
Zyxel Emg3525-t50b Firmware<=5.50\(abpm.9.5\)c0
Zyxel Emg3525-t50b
All of the following
Zyxel Emg5523-t50b Firmware<=5.50\(abpm.9.5\)c0
Zyxel Emg5523-t50b
All of the following
Zyxel Emg5723-t50k Firmware<=5.50\(abom.8.6\)c0
Zyxel Emg5723-t50k
All of the following
Zyxel Emg6726-b10a Firmware<=5.13\(abnp.8\)c0
Zyxel Emg6726-b10a
All of the following
Zyxel Gm4100-b0 Firmware<=5.18\(accl.1\)c0
Zyxel Gm4100-b0
All of the following
Zyxel VMG3625-T50B firmware<=5.50\(abpm.9.5\)c0
Zyxel VMG3625-T50B
All of the following
Zyxel Vmg3927-b50b Firmware<=5.13\(ably.10\)c0
Zyxel Vmg3927-b50b
All of the following
Zyxel Vmg3927-t50k Firmware<=5.50\(abom.8.6\)c0
Zyxel Vmg3927-t50k
All of the following
Zyxel VMG4005-B50A firmware<=5.17\(abqa.3\)c0
Zyxel VMG4005-B50A
All of the following
Zyxel Vmg4005-b60a Firmware<=5.17\(abqa.3\)c0
Zyxel Vmg4005-b60a
All of the following
Zyxel Vmg4005-b50b Firmware<=5.13\(abrl.5.3\)c0
Zyxel Vmg4005-b50b
All of the following
Zyxel Vmg4927-b50a Firmware<=5.13\(ably.10\)c0
Zyxel Vmg4927-b50a
All of the following
Zyxel Vmg8623-t50b Firmware<=5.50\(abpm.9.5\)c0
Zyxel Vmg8623-t50b
All of the following
Zyxel VMG8825-T50K firmware<=5.50\(abom.8.6\)c0
Zyxel VMG8825-T50K
All of the following
Zyxel AX7501-B0 firmware<=5.17\(abpc.6.1\)c0
Zyxel AX7501-B0
All of the following
Zyxel AX7501-B1 firmware<=5.17\(abpc.6.1\)c0
Zyxel AX7501-B1
All of the following
Zyxel Pe3301-00 Firmware<=5.63\(acmt.1.1\)c0
Zyxel Pe3301-00
All of the following
Zyxel Pe5301-01 Firmware<=5.63\(acoj.1.1\)c0
Zyxel Pe5301-01
All of the following
Zyxel Pm3100-t0 Firmware<=5.42\(acbf.3\)c0
Zyxel Pm3100-t0
All of the following
Zyxel Pm5100-t0 Firmware<=5.42\(acbf.3\)c0
Zyxel Pm5100-t0
All of the following
Zyxel Pm7500-00 Firmware<=5.61\(ackk.1\)c0
Zyxel Pm7500-00
All of the following
Zyxel Pm7300-t0 Firmware<=5.42\(abyy.3\)c0
Zyxel Pm7300-t0
All of the following
Zyxel Px3321-t1 Firmware<=5.44\(acjb.1.3\)c0
Zyxel Px3321-t1
All of the following
Zyxel Px3321-t1 Firmware<=5.44\(achk.1\)c0
Zyxel Px3321-t1
All of the following
Zyxel Px5301-t0 Firmware<=5.44\(ackb.0.4\)c0
Zyxel Px5301-t0
All of the following
Zyxel Scr 50axe Firmware<=1.10\(acgn.3\)c0
Zyxel Scr 50axe
All of the following
Zyxel We3300-00 Firmware<=5.70\(acka.0\)c0
Zyxel We3300-00
All of the following
Zyxel WX3100-T0 firmware<=5.50\(abvl.4.7\)c0
Zyxel WX3100-T0
All of the following
Zyxel Wx3401-b0 Firmware<=5.17\(abve.2.8\)c0
Zyxel Wx3401-b0
All of the following
Zyxel Wx3401-b1 Firmware<=5.17\(abve.2.8\)c0
Zyxel Wx3401-b1
All of the following
Zyxel Wx5600-t0 Firmware<=5.70\(aceb.4.1\)c0
Zyxel Wx5600-t0
All of the following
Zyxel Wx5610-b0 Firmware<=5.18\(acgj.0.3\)c0
Zyxel Wx5610-b0

Event History

Nov 18, 2025
CVE Published
via MITRE·01:19 AM
Data Sourced
via MITRE·01:19 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·02:15 AM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2025-6599?

CVE-2025-6599 has been classified as a high-severity vulnerability due to its potential to facilitate denial-of-service attacks.

2

How do I fix CVE-2025-6599?

To fix CVE-2025-6599, update the Zyxel DX3301-T0 firmware to a version later than 5.50(ABVY.6.3)C0.

3

What type of attack is possible with CVE-2025-6599?

CVE-2025-6599 enables Slowloris-style denial-of-service attacks against the affected web server.

4

What impact does CVE-2025-6599 have on users?

Users may experience temporary blocking of legitimate HTTP requests and partial service disruption due to CVE-2025-6599.

5

Which devices are affected by CVE-2025-6599?

CVE-2025-6599 affects the Zyxel DX3301-T0 firmware version 5.50(ABVY.6.3)C0 and earlier versions.

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