Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-23439— udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于udp_sock_create6函数在特定配置下返回成功但未创建套接字，可能导致空指针取消引用。

AI Predicted 7.8 Difficulty: Moderate EPSS 0.13% · P2

Possible ATT&CK Techniques 1 AI

T1203 · Exploitation for Client Execution

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux fd384412e199b62c3ddaabd18dce86d0e164c5b9< dfc96ae0074cc47b5478a59e5aa19233e434243f affected
fd384412e199b62c3ddaabd18dce86d0e164c5b9< 66117dbb3dbae82f86735bf727b1d59cc677afa1 affected
fd384412e199b62c3ddaabd18dce86d0e164c5b9< ba7c9ddcdd077942b798979edb035207374d4096 affected
fd384412e199b62c3ddaabd18dce86d0e164c5b9< a05a2149386f6dfb4245f522acdbef892acafc84 affected
fd384412e199b62c3ddaabd18dce86d0e164c5b9< 9f036aa0fe46c19e938f03d10e02c23f4fffae5e affected
fd384412e199b62c3ddaabd18dce86d0e164c5b9< 003343985f26dfefd0c94b1fe1316a2de74428b9 affected
fd384412e199b62c3ddaabd18dce86d0e164c5b9< 12aa4b73a67d95bc739995a2d6943aec2f9785c9 affected
fd384412e199b62c3ddaabd18dce86d0e164c5b9< b3a6df291fecf5f8a308953b65ca72b7fc9e015d affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-23439

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0 (success) without actually creating a socket. Callers such as fou_create() then proceed to dereference the uninitialized socket pointer, resulting in a NULL pointer dereference. The captured NULL deref crash: BUG: kernel NULL pointer dereference, address: 0000000000000018 RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764) [...] Call Trace: <TASK> genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114) genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209) [...] netlink_rcv_skb (net/netlink/af_netlink.c:2550) genl_rcv (net/netlink/genetlink.c:1219) netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) __sock_sendmsg (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1)) __sys_sendto (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:2183 (discriminator 1)) __x64_sys_sendto (net/socket.c:2213 (discriminator 1) net/socket.c:2209 (discriminator 1) net/socket.c:2209 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (net/arch/x86/entry/entry_64.S:130) This patch makes udp_sock_create6 return -EPFNOSUPPORT instead, so callers correctly take their error paths. There is only one caller of the vulnerable function and only privileged users can trigger it.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于udp_sock_create6函数在特定配置下返回成功但未创建套接字，可能导致空指针取消引用。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux fd384412e199b62c3ddaabd18dce86d0e164c5b9 ~ dfc96ae0074cc47b5478a59e5aa19233e434243f -
Linux Linux 3.18 -

II. Public POCs for CVE-2026-23439

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-23439

请登录查看更多情报信息。

Same Patch Batch · Linux · 2026-04-03 · 71 CVEs total

CVE-2026-31402 9.8 CRITICAL nfsd: fix heap overflow in NFSv4.0 LOCK replay cache
CVE-2026-23450 9.8 CRITICAL net/smc: fix NULL dereference and UAF in smc_tcp_syn_recv_sock()
CVE-2026-23427 9.8 CRITICAL ksmbd: fix use-after-free in durable v2 replay of active file handles
CVE-2026-23428 9.8 CRITICAL ksmbd: fix use-after-free of share_conf in compound request
CVE-2026-23455 9.1 CRITICAL netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()
CVE-2026-23461 8.8 HIGH Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user
CVE-2026-23425 8.8 HIGH KVM: arm64: Fix ID register initialization for non-protected pKVM guests
CVE-2026-23462 8.8 HIGH Bluetooth: HIDP: Fix possible UAF
CVE-2026-23457 8.6 HIGH netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()
CVE-2026-23459 8.2 HIGH ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS
CVE-2026-23456 8.2 HIGH netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case
CVE-2026-31393 8.1 HIGH Bluetooth: L2CAP: Validate L2CAP_INFO_RSP payload length before access
CVE-2026-31392 8.1 HIGH smb: client: fix krb5 mount with username option
CVE-2026-31401 7.8 HIGH HID: bpf: prevent buffer overflow in hid_hw_request
CVE-2026-23466 7.8 HIGH drm/xe: Open-code GGTT MMIO access protection
CVE-2026-23437 7.8 HIGH net: shaper: protect late read accesses to the hierarchy
CVE-2026-23458 7.8 HIGH netfilter: ctnetlink: fix use-after-free in ctnetlink_dump_exp_ct()
CVE-2026-23444 7.8 HIGH wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure
CVE-2026-23445 7.8 HIGH igc: fix page fault in XDP TX timestamps handling
CVE-2026-23449 7.8 HIGH net/sched: teql: Fix double-free in teql_master_xmit

Showing top 20 of 71 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-23439

No comments yet

Leave a comment