Linux Kernel up to 7.0-rc1 get_upper_ifindexes out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.17

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 7.0-rc1. This issue affects the function get_upper_ifindexes. The manipulation leads to out-of-bounds write. This vulnerability is listed as CVE-2026-23359. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.0-rc1 and classified as critical. This issue affects the function get_upper_ifindexes. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stack-out-of-bounds write in devmap get_upper_ifindexes() iterates over all upper devices and writes their indices into an array without checking bounds. Also the callers assume that the max number of upper devices is MAX_NEST_DEV and allocate excluded_devices[1+MAX_NEST_DEV] on the stack, but that assumption is not correct and the number of upper devices could be larger than MAX_NEST_DEV (e.g., many macvlans), causing a stack-out-of-bounds write. Add a max parameter to get_upper_ifindexes() to avoid the issue. When there are too many upper devices, return -EOVERFLOW and abort the redirect. To reproduce, create more than MAX_NEST_DEV(8) macvlans on a device with an XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS. Then send a packet to the device to trigger the XDP redirect path.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-23359 since 01/13/2026. The exploitation is known to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 303736 (Linux Distros Unpatched Vulnerability : CVE-2026-23359), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7 or 7.0-rc2 eliminates this vulnerability. Applying the patch 5000e40acc8d0c36ab709662e32120986ac22e7e/8a95fb9df1105b1618872c2846a6c01e3ba20b45/d2c31d8e03d05edc16656e5ffe187f0d1da763d7/75d474702b2ba8b6bcb26eb3004dbc5e95ffd5d2/ca831567908fd3f73cf97d8a6c09a5054697a182/b7bf516c3ecd9a2aae2dc2635178ab87b734fef1 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 vulnerability database at Tenable (303736). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 303736
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23359

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.167/6.6.130/6.12.77/6.18.17/6.19.7/7.0-rc2
Patch: 5000e40acc8d0c36ab709662e32120986ac22e7e/8a95fb9df1105b1618872c2846a6c01e3ba20b45/d2c31d8e03d05edc16656e5ffe187f0d1da763d7/75d474702b2ba8b6bcb26eb3004dbc5e95ffd5d2/ca831567908fd3f73cf97d8a6c09a5054697a182/b7bf516c3ecd9a2aae2dc2635178ab87b734fef1

Timelineinfo

01/13/2026 CVE reserved
03/25/2026 +71 days Advisory disclosed
03/25/2026 +0 days VulDB entry created
03/30/2026 +5 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23359 (🔒)
GCVE (CVE): GCVE-0-2026-23359
GCVE (VulDB): GCVE-100-353093

Entryinfo

Created: 03/25/2026 13:30
Updated: 03/30/2026 10:38
Changes: 03/25/2026 13:30 (58), 03/26/2026 07:25 (2), 03/30/2026 10:38 (1)
Complete: 🔍
Cache ID: 216:E70:103

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