Cybersecurity servers

150 measured server(s) with the Cybersecurity sub-topic, ranked by real members. Browse topics →

Server	Members	Online	Active
1 Kali Linux & Friends	72,487	4,779	6.6%
2 ImaginaryCTF	14,163	1,927	13.6%
3 CTFlearn	12,101	1,005	8.3%
4 CryptoHack	10,787	1,669	15.5%
5 AI Security Engineers	10,136	734	7.2%
6 THE NEMICO NETWORK📡	8,140	779	9.6%
7 SECCON Beginners CTF	6,749	1,021	15.1%
8 Hackless 🥷	6,604	20	0.3%
9 FCSC & Hackropole	6,095	1,090	17.9%
10 SkillBit (formerly MetaCTF)	6,087	714	11.7%
11 Parrot Security	5,901	339	5.7%
12 Practical Networking	5,582	250	4.5%
13 GoogleCTF	5,536	1,044	18.9%
14 SekaiCTF 2026	5,242	1,075	20.5%
15 404 CTF	4,620	842	18.2%
16 HITCON CTF	4,056	907	22.4%
17 VishwaCTF	4,020	164	4.1%
18 ångstromCTF	3,995	336	8.4%
19 Digital Forensics	3,976	650	16.3%
20 UIUCTF 2026	3,749	537	14.3%
21 Real World CTF	3,748	288	7.7%
22 Midnight Sun CTF	3,624	802	22.1%
23 nullcon HackIM 2026	3,499	244	7.0%
24 ASIS CTF	3,450	585	17.0%
25 UTCTF 2026	3,425	606	17.7%
26 PatriotCTF 2026	3,379	665	19.7%
27 InfoSec VPN	3,356	40	1.2%
28 scriptCTF	3,291	353	10.7%
29 Deep Hat	3,235	248	7.7%
30 Techies Hideaway	3,226	514	15.9%
31 idekCTF	3,213	538	16.7%
32 247CTF	3,188	244	7.7%
33 b01lersCTF	3,132	346	11.0%
34 SunshineCTF	3,124	299	9.6%
35 UMassCTF 2026	3,072	321	10.4%
36 BlueCapeSecurity	3,019	219	7.3%
37 BuckeyeCTF 2025	2,934	358	12.2%
38 WormGPT Official	2,929	94	3.2%
39 Kaspersky{CTF}	2,753	293	10.6%
40 KalmarCTF	2,743	649	23.7%
41 corCTF	2,741	504	18.4%
42 Dex Security	2,672	150	5.6%
43 HSCTF	2,640	198	7.5%
44 Official HackMyVM	2,629	105	4.0%
45 CrewCTF 2025	2,606	315	12.1%
46 KnightCTF	2,597	190	7.3%
47 TSG CTF	2,556	266	10.4%
48 smileyCTF 2025	2,511	290	11.5%
49 GPN CTF 2026	2,455	503	20.5%
50 XCTF 10th–SCTF 2026	2,447	107	4.4%
51 niteCTF '25	2,447	226	9.2%
52 rCTF	2,422	184	7.6%
53 Midnight Flag CTF - EXECUTION	2,366	546	23.1%
54 DIVER OSINT CTF	2,345	570	24.3%
55 CISO Assistant - GRC community	2,289	96	4.2%
56 R3CTF 2026	2,202	294	13.4%
57 NNS CTF	2,196	520	23.7%
58 HACKTORIA	2,169	213	9.8%
59 UMDCTF 2026	2,116	355	16.8%
60 1753CTF	2,108	190	9.0%
61 b01lers	2,074	198	9.5%
62 Rhino Security Labs	2,050	203	9.9%
63 DEADFACE CTF	1,968	269	13.7%
64 JerseyCTF 🔒	1,967	187	9.5%
65 Hack.lu CTF	1,942	284	14.6%
66 HackDay	1,921	264	13.7%
67 Dev Universe - FGTE CTF	1,914	172	9.0%
68 SECCON CTF 14	1,909	352	18.4%
69 BCACTF	1,888	187	9.9%
70 CTF@CIT	1,876	217	11.6%
71 jailCTF 2026	1,793	229	12.8%
72 Cyber Odyssey: Akasec CTF	1,792	75	4.2%
73 zer0pts CTF	1,775	204	11.5%
74 InCTF Nationals	1,764	59	3.3%
75 N0PSctf	1,748	193	11.0%
76 SECCON CTF 13	1,724	257	14.9%
77 IrisCTF	1,702	219	12.9%
78 Equinor CTF	1,662	295	17.7%
79 BlahajCTF	1,602	261	16.3%
80 Maltego Community OSINT	1,570	156	9.9%
81 DamCTF	1,532	174	11.4%
82 pwnable.tw	1,518	177	11.7%
83 ECW CTF	1,433	211	14.7%
84 TetCTF	1,433	142	9.9%
85 TAMUctf 2026	1,413	173	12.2%
86 xCTFs	1,408	293	20.8%
87 CyberDawgs Club	1,403	168	12.0%
88 RITSEC CTF	1,397	206	14.7%
89 SECCON CTF 2023	1,363	171	12.5%
90 BSides Tampa	1,311	117	8.9%
91 Sieberrsec CTF	1,309	140	10.7%
92 @Hack CTF - Concordia	1,300	68	5.2%
93 CyberSpace CTF 2024	1,298	122	9.4%
94 Arqora	1,291	98	7.6%
95 hackerspace - DropCTF	1,279	200	15.6%
96 CakeCTF 2023	1,279	137	10.7%
97 ISITDTU-CTF	1,262	156	12.4%
98 ELORIA	1,245	60	4.8%
99 Hack In The North	1,242	16	1.3%
100 AlpacaHack	1,224	227	18.5%
101 WaniCTF	1,222	163	13.3%
102 wpictf	1,185	45	3.8%
103 DaVinciCTF	1,150	124	10.8%
104 UnitedCTF	1,138	92	8.1%
105 HKCERT CTF 2024	1,129	175	15.5%
106 Shutlock CTF 🕵	1,120	168	15.0%
107 RingZer0 CTF	1,116	159	14.2%
108 FAUST CTF 2026	1,113	152	13.7%
109 pingCTF 2026	1,108	80	7.2%
110 BDSec CTF	1,102	109	9.9%
111 NCKUCTF	1,087	317	29.2%
112 SaaS Alerts	1,084	143	13.2%
113 Swiss Hacking Challenge	1,082	111	10.3%
114 RACTF	1,072	69	6.4%
115 DFIR-IRIS	1,063	108	10.2%
116 Paradigm CTF	1,061	131	12.3%
117 squ1rrel CTF 2026	1,042	133	12.8%
118 Olympics CTF	1,032	99	9.6%
119 x3CTF 2026	1,017	123	12.1%
120 IRON CTF 2024	1,008	73	7.2%
121 Pragyan CTF'26	1,003	85	8.5%
122 PearlCTF	997	75	7.5%
123 BSides Atlanta	971	85	8.8%
124 HTB Meetups Mexico	960	50	5.2%
125 SwampCTF	950	87	9.2%
126 Break the Syntax CTF	943	71	7.5%
127 SpookyCTF	942	83	8.8%
128 Arab & Africa Regional CTF	939	23	2.4%
129 CISSP・CBKを中心としたセキュリティ学習WG	933	81	8.7%
130 pwnable.kr	920	117	12.7%
131 P3rf3ctr00t CTF	905	43	4.8%
132 BRICS+ CTF	894	71	7.9%
133 pwntools	893	95	10.6%
134 DEF CON Group Trivandrum	890	11	1.2%
135 Wargames.MY CTF 2024	889	55	6.2%
136 NewbieContest	887	49	5.5%
137 Wizer CTF	814	39	4.8%
138 Cryptocracy™	795	22	2.8%
139 07CTF	781	110	14.1%
140 EnigmaXplore 3.0	781	37	4.7%
141 snakeCTF	778	71	9.1%
142 HACK'OSINT - CTF	766	48	6.3%
143 DAMSEC CTF LEAGUE	765	122	15.9%
144 BH CTF	737	67	9.1%
145 TSCCTF 2026	707	150	21.2%
146 PolyU NuttyShell CTF Competition	705	99	14.0%
147 San Diego CTF 2022	697	35	5.0%
148 Uni Bonn Community CTF	692	30	4.3%
149 HKCERT CTF 2023	680	86	12.6%
150 Crate-CTF	667	102	15.3%