CVE-2026-23459 ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS

What is CVE-2026-23459?

CVE-2026-23459 is a high-severity memory corruption vulnerability in Linux kernel, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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

ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS

Blamed commits forgot that vxlan/geneve use udp_tunnel[6]_xmit_skb() which call iptunnel_xmit_stats().

iptunnel_xmit_stats() was assuming tunnels were only using NETDEV_PCPU_STAT_TSTATS.

@syncp offset in pcpu_sw_netstats and pcpu_dstats is different.

32bit kernels would either have corruptions or freezes if the syncp sequence was overwritten.

This patch also moves pcpu_stat_type closer to dev->{t,d}stats to avoid a potential cache line miss since iptunnel_xmit_stats() needs to read it.

Which versions are affected by CVE-2026-23459?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23459?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-23459 being exploited?

There is no known exploitation of CVE-2026-23459 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-103419, BELL-CVE-2026-23459, DEBIAN-CVE-2026-23459, GHSA-gv4g-88q2-j2qq, UBUNTU-CVE-2026-23459.