PT-2026-28331 · Linux+1 · Linux Kernel+1
Published
2026-01-01
·
Updated
2026-05-21
·
CVE-2026-23398
CVSS v2.0
7.8
High
| Vector | AV:N/AC:L/Au:N/C:N/I:N/A:C |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The Linux kernel contains a flaw within the
icmp tag validation() function. This function unconditionally dereferences a pointer without a preceding NULL check. Specifically, it dereferences the result of rcu dereference(inet protos[proto]) without verifying if it is NULL. The inet protos[] array is sparsely populated, with only a limited number of protocol handlers registered. When the ip no pmtu disc setting is configured to 3 (hardened PMTU mode), and the kernel processes an ICMP Fragmentation Needed error containing an unregistered protocol number, a NULL dereference occurs, leading to a kernel panic in the softirq context. The function icmp unreach is involved in the call trace. A fix involves adding a NULL check before accessing icmp strict tag validation, returning false if no handler is registered.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
DoS
NULL Pointer Dereference
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Weakness Enumeration
Related Identifiers
Affected Products
Linux Kernel
Red Os