The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - icmp: fix NULL pointer dereference in icmp_tag_validation() icmp_tag_validation() unconditionally     dereferences the result of rcu_dereference(inet_protos[proto]) without checking for NULL. The     inet_protos[] array is sparse -- only about 15 of 256 protocol numbers have registered handlers. When     ip_no_pmtu_disc is set to 3 (hardened PMTU mode) and the kernel receives an ICMP Fragmentation Needed     error with a quoted inner IP header containing an unregistered protocol number, the NULL dereference     causes a kernel panic in softirq context. Oops: general protection fault, probably for non-canonical     address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range     [0x0000000000000010-0x0000000000000017] RIP: 0010:icmp_unreach (net/ipv4/icmp.c:1085 net/ipv4/icmp.c:1143)     Call Trace: <IRQ> icmp_rcv (net/ipv4/icmp.c:1527) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:207)     ip_local_deliver_finish (net/ipv4/ip_input.c:242) ip_local_deliver (net/ipv4/ip_input.c:262) ip_rcv     (net/ipv4/ip_input.c:573) __netif_receive_skb_one_core (net/core/dev.c:6164) process_backlog     (net/core/dev.c:6628) handle_softirqs (kernel/softirq.c:561) </IRQ> Add a NULL check before accessing     icmp_strict_tag_validation. If the protocol has no registered handler, return false since it cannot     perform strict tag validation. (CVE-2026-23398)

Note that Nessus relies on the presence of the package as reported by the vendor.

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Linux Distros Unpatched Vulnerability : CVE-2026-23398

medium Nessus Plugin ID 303887

Version 1.8

Version 1.7

Version 1.6

Version 1.5

Version 1.4

Version 1.3

Version 1.2

Version 1.8 May 3, 2026, 4:59 AM Detection (updated detection logic) Plugin metadata Plugin Feed: 202605030459
Version 1.7 May 2, 2026, 11:12 PM Detection (updated detection logic) Plugin metadata Plugin Feed: 202605022312
Version 1.6 Apr 9, 2026, 9:45 AM CVSS temporal metrics ("CVSSv2 temporal vector" set to "CVSS2#E:POC/RL:U/RC:C") CVSS temporal metrics ("CVSSv3 temporal vector" set to "CVSS:3.0/E:P/RL:U/RC:C") Exploit attributes ("Exploit available" set to "True") Exploit attributes ("Exploitability ease" changed from "No known exploits are available" to "Exploits are available") Plugin Feed: 202604090945
Version 1.5 Apr 4, 2026, 11:10 PM Detection (updated detection logic) Plugin metadata Plugin Feed: 202604042310
Version 1.4 Apr 3, 2026, 8:06 AM Detection (updated detection logic) Plugin metadata Plugin Feed: 202604030806
Version 1.3 Mar 31, 2026, 4:03 AM Detection (updated detection logic) Plugin metadata Plugin Feed: 202603310403
Version 1.2 Mar 27, 2026, 2:12 PM CVSS metrics ("CVSSv2 score" set to 4.9. "CVSSv2 vector" set to "CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C". "CVSSv3 score" set to 5.5. "CVSSv3 vector" set to "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H") CVSSv2 severity (based on CVE-2026-23398, severity decreased from "High" to "Medium") CVSSv3 severity (based on None, severity decreased from "High" to "Medium") Detection (updated detection logic) New Plugin metadata Plugin Feed: 202603271412