Linux Kernel up to 6.19.11 br_nd_send opt[] buffer overflow

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.19.11 and classified as critical. Affected by this issue is the function br_nd_send. The manipulation of the argument opt[] results in buffer overflow. This vulnerability is known as CVE-2026-31682. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.19.11. Affected is the function br_nd_send. The manipulation of the argument opt[] with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bridge: br_nd_send: linearize skb before parsing ND options br_nd_send() parses neighbour discovery options from ns->opt[] and assumes that these options are in the linear part of request. Its callers only guarantee that the ICMPv6 header and target address are available, so the option area can still be non-linear. Parsing ns->opt[] in that case can access data past the linear buffer. Linearize request before option parsing and derive ns from the linear network header.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-31682 since 03/09/2026. The exploitability is told to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 04/26/2026).

The vulnerability scanner Nessus provides a plugin with the ID 310339 (Linux Distros Unpatched Vulnerability : CVE-2026-31682), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22 or 6.19.12 eliminates this vulnerability. Applying the patch c68433fd291c9e88c00292095172c62d1997d662/4f397b950c916e9a1f8a4fce04ea0110206cad47/bd91ec85aa4c77d645bd2739fc56784157a88ca2/658261898130da620fc3d0fbb0523efb3366cb55/2ba4caba423ed94d63006eb1d2227b0332ab7fcd/9c55e41c73af5c4511070933b1bd25248521270c/3a30f6469b058574f49efde61cd6f5d79e576053/a01aee7cafc575bb82f5529e8734e7052f9b16ea 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 (310339) and EUVD (EUVD-2026-25649). Once again VulDB remains the best source for vulnerability data.

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

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / 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: 310339
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-31682

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.253/5.15.203/6.1.168/6.6.134/6.12.81/6.18.22/6.19.12
Patch: c68433fd291c9e88c00292095172c62d1997d662/4f397b950c916e9a1f8a4fce04ea0110206cad47/bd91ec85aa4c77d645bd2739fc56784157a88ca2/658261898130da620fc3d0fbb0523efb3366cb55/2ba4caba423ed94d63006eb1d2227b0332ab7fcd/9c55e41c73af5c4511070933b1bd25248521270c/3a30f6469b058574f49efde61cd6f5d79e576053/a01aee7cafc575bb82f5529e8734e7052f9b16ea

Timelineinfo

03/09/2026 CVE reserved
04/25/2026 +46 days Advisory disclosed
04/25/2026 +0 days VulDB entry created
04/26/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-31682 (🔒)
GCVE (CVE): GCVE-0-2026-31682
GCVE (VulDB): GCVE-100-359580
EUVD: 🔒

Entryinfo

Created: 04/25/2026 11:33
Updated: 04/26/2026 05:51
Changes: 04/25/2026 11:33 (59), 04/25/2026 13:02 (1), 04/26/2026 05:51 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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