NebulaFlex Switch XGS1935 Series - V4.90 Patch 1 Firmware Release

Zyxel_Melen · August 28

Zyxel Switch XGS1935 Series Release Note

August 2025

Firmware Version on all models

(Click Hyperlink to download the firmware directly)

Zyxel XGS1935-28HP - V4.90(ACJX.1)C0

Zyxel XGS1935-28 - V4.90(ACJW.1)C0

Zyxel XGS1935-52HP - V4.90(ACJZ.1)C0

Zyxel XGS1935-52 - V4.90(ACJY.1)C0

New Feature and Enhancements

Bug Fix

C=Cloud mode, S=Standalone mode

Bug fix	C	S
1. [eITS #240501702] Fixed device IP address and uplink usage are not displayed correctly on Nebula.	V	-
2. [eITS #241100262] Cannot clear classifier names longer than 10 characters.	-	V
3. [eITS #241100288] MSTP root guard cannot prevent the RSTP-superior switch from preempting the Root	-	V
4. [eITS #241100538] Fixed special characters (space, ' ," ) can be allowed in username to cause configuration error.	-	V
5. [eITS #241200595] Fixed high CPU usage triggered by client switching between trunk interfaces.	V	V
6. [eITS #250100026] Fixed abnormal crash issue when continues queries OID 1.0.8802.1.1.2.1.5.4795.1.2.1.1 and its sub-OIDs.	V	V
7. [eITS #250100440] Fixed that truncated DNS packets cannot be process to cause DNS parsing failed.	V	V
8. [eITS #250201088] When the RADIUS server does not provide a session- timeout attribute, the switch will re- authenticate successfully connected devices every hour by default.	V	V
9. [eITS #250200357] The switch has dropped the EAPoL unicast packet.	V	V
10. [eITS #250302409] Fixed the device sometimes fail to connect with Nebula server.	V	-
11. [eITS #250500429] Fixed crash when receiving IPv6 tunnel packet.	-	V
12. [eITS #250500683] Voice VLAN (via LLDP MED) does not work properly when enabling MAC-auth under NCC cloud authentication.	V	-
13. [eITS #250601084] Fixed hang when using CLI “show tech-support”.	V	V
14. [eITS #250601569] When the default gateway is configured with a link-local address, the IPv6 routing table may display abnormal/incorrect information for the next hop.	-	V
15. [eITS #250301742, 250600412] Supplicants that have successfully passed 802.1X authentication may still be incorrectly assigned to guest VLAN if the reachability of RADIUS server is unstable.	-	V

Please refer to the Download Link for more details.