VulnerabilityPublished 6 Oct 2026Updated 19 Oct 2026

CVE-2026-98240: Linux kernel · net: ip_tunnel: initialize `options_len` before referencing options

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 9907325257b4b382f26aafd5d9a8d47915907dd5 : patch Linux kernel soon.

Data as of 26 Oct 2026, 12:55 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9907325257b4b382f26aafd5d9a8d47915907dd5, 455ebeadf714f51e1dbbd6a022c74c9215b1cd76, 0f6a6beb01c068fcd5274eabf22c260039749fea

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to 9907325257b4b382f26aafd5d9a8d47915907dd5, 455ebeadf714f51e1dbbd6a022c74c9215b1cd76 or 0f6a6beb01c068fcd5274eabf22c260039749fea.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ bb5e62f2d547c4de6d1b144cbce2373a76c33f18, < 9907325257b4b382f26aafd5d9a8d47915907dd5	Fixed in 9907325257b4b382f26aafd5d9a8d47915907dd5
LinuxLinux	Affected ≥ bb5e62f2d547c4de6d1b144cbce2373a76c33f18, < 455ebeadf714f51e1dbbd6a022c74c9215b1cd76	Fixed in 455ebeadf714f51e1dbbd6a022c74c9215b1cd76
LinuxLinux	Affected ≥ bb5e62f2d547c4de6d1b144cbce2373a76c33f18, < 0f6a6beb01c068fcd5274eabf22c260039749fea	Fixed in 0f6a6beb01c068fcd5274eabf22c260039749fea
LinuxLinux	Affected =6.15	Fixed in–

AI-suggested

A fix is available and has been applied in the Linux kernel source. Users should update to a fixed kernel version containing the patch that initializes 'options_len' before use. No additional mitigation is required once the kernel is updated.

Description

A vulnerability in the Linux kernel's ip_tunnel module caused a kernel panic due to an uninitialized variable 'options_len' being used before assignment. This led to a buffer overflow detected by fortified memcpy calls on kernels built with GCC 15+ and CONFIG_FORTIFY_SOURCE. The issue was fixed by properly initializing the counter before referencing options.

Impact

The vulnerability causes a kernel panic (denial of service) when certain ip route commands involving Geneve options are executed. This can disrupt system operations but does not indicate code execution or privilege escalation. The issue is triggered by malformed network configuration commands that lead to a buffer overflow detected by fortified memcpy, causing the kernel to abort.

Summary

CVE-2026-98240 describes a flaw in the Linux kernel ip_tunnel code where the variable 'options_len' was not initialized before being used to calculate an offset for copying Geneve options data. This caused a zero-sized destination buffer to be passed to memcpy, triggering a buffer overflow detection and kernel panic on affected systems. The problem occurs specifically on kernels compiled with GCC 15 or newer with CONFIG_FORTIFY_SOURCE enabled. The fix involved initializing 'options_len' prior to its use, aligning with the behavior of the related function 'tunnel_key_opts_set()'.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 12:08 UTC

Technical details

References

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