Linux Kernel up to 6.19.5 CPER section_length 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, which was classified as critical, was found in Linux Kernel up to 6.19.5. Affected by this vulnerability is an unknown functionality of the component CPER. The manipulation of the argument section_length results in buffer overflow. This vulnerability is reported as CVE-2026-43266. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.19.5. It has been classified as critical. Affected is some unknown functionality of the component CPER. The manipulation of the argument section_length 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: EFI/CPER: don't go past the ARM processor CPER record buffer There's a logic inside GHES/CPER to detect if the section_length is too small, but it doesn't detect if it is too big. Currently, if the firmware receives an ARM processor CPER record stating that a section length is big, kernel will blindly trust section_length, producing a very long dump. For instance, a 67 bytes record with ERR_INFO_NUM set 46198 and section length set to 854918320 would dump a lot of data going a way past the firmware memory-mapped area. Fix it by adding a logic to prevent it to go past the buffer if ERR_INFO_NUM is too big, making it report instead: [Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 1 [Hardware Error]: event severity: recoverable [Hardware Error]: Error 0, type: recoverable [Hardware Error]: section_type: ARM processor error [Hardware Error]: MIDR: 0xff304b2f8476870a [Hardware Error]: section length: 854918320, CPER size: 67 [Hardware Error]: section length is too big [Hardware Error]: firmware-generated error record is incorrect [Hardware Error]: ERR_INFO_NUM is 46198 [ rjw: Subject and changelog tweaks ]

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-43266 since 05/01/2026. The exploitability is told to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 05/07/2026).

The vulnerability scanner Nessus provides a plugin with the ID 312818 (Linux Distros Unpatched Vulnerability : CVE-2026-43266), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16 or 6.19.6 eliminates this vulnerability. Applying the patch c80113dcfc807308f5ab33847fae77e07531aeb8/ca2aad8771aa9091bc9e42e7d546bd40b72ddcd4/a68d22902a6916e10ee235fee609239004e129d0/64eb63f573f497553e1a0c388bbcdd639e0f0704/be10c1bdf64a39832998f54900aa309b3917abcf/25b290624b0e3d2f0f90238709ee0b6009b9fde8/45766863baf899059e75595dd3cb1116467f2095/eae21beecb95a3b69ee5c38a659f774e171d730e 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 (312818). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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Version

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Website

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: 312818
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-43266

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.252/5.15.202/6.1.165/6.6.128/6.12.75/6.18.16/6.19.6
Patch: c80113dcfc807308f5ab33847fae77e07531aeb8/ca2aad8771aa9091bc9e42e7d546bd40b72ddcd4/a68d22902a6916e10ee235fee609239004e129d0/64eb63f573f497553e1a0c388bbcdd639e0f0704/be10c1bdf64a39832998f54900aa309b3917abcf/25b290624b0e3d2f0f90238709ee0b6009b9fde8/45766863baf899059e75595dd3cb1116467f2095/eae21beecb95a3b69ee5c38a659f774e171d730e

Timelineinfo

05/01/2026 CVE reserved
05/06/2026 +5 days Advisory disclosed
05/06/2026 +0 days VulDB entry created
05/07/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43266 (🔒)
GCVE (CVE): GCVE-0-2026-43266
GCVE (VulDB): GCVE-100-361482

Entryinfo

Created: 05/06/2026 16:54
Updated: 05/07/2026 17:34
Changes: 05/06/2026 16:54 (59), 05/07/2026 17:34 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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