Linux Kernel up to 6.18.3/6.19-rc3 ERSPAN ip_tunnel_info_opts_set denial of service

CVSS Meta Temp Score
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5.0$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.3/6.19-rc3. It has been rated as critical. This impacts the function ip_tunnel_info_opts_set of the component ERSPAN Handler. The manipulation leads to denial of service. This vulnerability is referenced as CVE-2025-71128. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.3/6.19-rc3. This issue affects the function ip_tunnel_info_opts_set of the component ERSPAN Handler. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: erspan: Initialize options_len before referencing options. The struct ip_tunnel_info has a flexible array member named options that is protected by a counted_by(options_len) attribute. The compiler will use this information to enforce runtime bounds checking deployed by FORTIFY_SOURCE string helpers. As laid out in the GCC documentation, the counter must be initialized before the first reference to the flexible array member. After scanning through the files that use struct ip_tunnel_info and also refer to options or options_len, it appears the normal case is to use the ip_tunnel_info_opts_set() helper. Said helper would initialize options_len properly before copying data into options, however in the GRE ERSPAN code a partial update is done, preventing the use of the helper function. Before this change the handling of ERSPAN traffic in GRE tunnels would cause a kernel panic when the kernel is compiled with GCC 15+ and having FORTIFY_SOURCE configured: memcpy: detected buffer overflow: 4 byte write of buffer size 0 Call Trace: <IRQ> __fortify_panic+0xd/0xf erspan_rcv.cold+0x68/0x83 ? ip_route_input_slow+0x816/0x9d0 gre_rcv+0x1b2/0x1c0 gre_rcv+0x8e/0x100 ? raw_v4_input+0x2a0/0x2b0 ip_protocol_deliver_rcu+0x1ea/0x210 ip_local_deliver_finish+0x86/0x110 ip_local_deliver+0x65/0x110 ? ip_rcv_finish_core+0xd6/0x360 ip_rcv+0x186/0x1a0 Reported-at: https://launchpad.net/bugs/2129580

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2025-71128 since 01/13/2026. The exploitation is known to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 302766 (Ubuntu 24.04 LTS / 25.10 : Linux kernel vulnerabilities (USN-8094-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.4 or 6.19-rc4 eliminates this vulnerability. Applying the patch b282b2a9eed848587c1348abdd5d83fa346a2743/35ddf66c65eff93fff91406756ba273600bf61a3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (302766) and CERT Bund (WID-SEC-2026-0119). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Open Source Linux Kernel

Productinfo

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Name

Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 302766
Nessus Name: Ubuntu 24.04 LTS / 25.10 : Linux kernel vulnerabilities (USN-8094-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.4/6.19-rc4
Patch: b282b2a9eed848587c1348abdd5d83fa346a2743/35ddf66c65eff93fff91406756ba273600bf61a3

Timelineinfo

01/13/2026 CVE reserved
01/14/2026 +1 days Advisory disclosed
01/14/2026 +0 days VulDB entry created
03/25/2026 +70 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-71128 (🔒)
GCVE (CVE): GCVE-0-2025-71128
GCVE (VulDB): GCVE-100-341075
CERT Bund: WID-SEC-2026-0119 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 01/14/2026 17:28
Updated: 03/25/2026 22:03
Changes: 01/14/2026 17:28 (59), 01/16/2026 05:59 (7), 03/18/2026 19:02 (2), 03/25/2026 22:03 (12)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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