CVE-2026-23398NULL Pointer Dereference in Linux

Severity
8.2HIGH
No vector
EPSS
0.0%
top 90.94%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedMar 26
Latest updateApr 20

Description

In the Linux kernel, the following vulnerability has been resolved: 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 heade

Affected Packages5 packages

Linuxlinux/linux_kernel3.14.06.1.167+4
Debianlinux/linux_kernel< 6.19.10-1
CVEListV5linux/linux8ed1dc44d3e9e8387a104b1ae8f92e9a3fbf1b1e1f9f2c6d4b2a613b7756fc5679c5116ba2ca0161+6
debiandebian/linux< linux 6.19.10-1 (forky)

🔴Vulnerability Details

4
VulDB
Linux Kernel up to 7.0-rc4 net/ipv4/icmp.c icmp_tag_validation inet_protos[] null pointer dereference (EUVD-2026-16158 / WID-SEC-2026-0879)2026-04-20
GHSA
GHSA-x3j5-9ghr-8cwm: In the Linux kernel, the following vulnerability has been resolved: icmp: fix NULL pointer dereference in icmp_tag_validation() icmp_tag_validation(2026-03-26
OSV
icmp: fix NULL pointer dereference in icmp_tag_validation()2026-03-26
OSV
CVE-2026-23398: In the Linux kernel, the following vulnerability has been resolved: icmp: fix NULL pointer dereference in icmp_tag_validation() icmp_tag_validation()2026-03-26

📋Vendor Advisories

3
Red Hat
kernel: icmp: fix NULL pointer dereference in icmp_tag_validation()2026-03-26
Microsoft
icmp: fix NULL pointer dereference in icmp_tag_validation()2026-03-10
Debian
CVE-2026-23398: linux - In the Linux kernel, the following vulnerability has been resolved: icmp: fix N...2026

🕵️Threat Intelligence

59
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CVE-2026-23266 Impact, Exploitability, and Mitigation Steps | Wiz