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CVE-2026-98240

In the Linux kernel, the following vulnerability has been resolved: net: ip_tunnel: initialize `options_len` before referencing options The following command triggers a kernel panic: ip link a…

Published Oct 6, 2026EPSS 0.18%

Overview

CVE-2026-98240 is a known-severity vulnerability. It was published on October 6, 2026.

Technical description

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

net: ip_tunnel: initialize `options_len` before referencing options

The following command triggers a kernel panic:

ip link add d0 type dummy; ip link set d0 up

ip route add 10.30.0.0/16 \

encap ip id 300 geneve_opts 4660:66:11223344 dev d0

memcpy: detected buffer overflow: 4 byte write of buffer size 0

kernel BUG at lib/string_helpers.c:1044!

...

ip_tun_parse_opts.part.0.cold+0x10/0x10

ip_tun_build_state+0x116/0x2a0

On kernels built with GCC 15+ and `CONFIG_FORTIFY_SOURCE`, the fortified

`memcpy()` got 0 sized destination with request of 4 bytes length:

static int ip_tun_parse_opts_geneve(...)

{

...

attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];

data_len = nla_len(attr); /* == 4 */

struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;

memcpy(opt->opt_data, nla_data(attr), data_len);

/* ^^^^^^^^^^^^^ 0 since options_len is assigned afterwards */

Fix

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Frequently asked questions

What is CVE-2026-98240?

CVE-2026-98240 is a known-severity vulnerability. It was published on October 6, 2026.

How severe is CVE-2026-98240?

CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.

How do I fix or remediate CVE-2026-98240?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-98240?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-98240 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

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