Linux Kernel up to 6.6.135/6.12.82/6.18.23/6.19.13 xdp_umem_reg buffer overflow

CVSS Meta Temp Score
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CTI Interest Score
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7.7$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.6.135/6.12.82/6.18.23/6.19.13. Affected by this vulnerability is the function xdp_umem_reg. Such manipulation leads to buffer overflow. This vulnerability is listed as CVE-2026-43093. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.135/6.12.82/6.18.23/6.19.13 and classified as critical. Affected by this issue is the function xdp_umem_reg. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: xsk: tighten UMEM headroom validation to account for tailroom and min frame The current headroom validation in xdp_umem_reg() could leave us with insufficient space dedicated to even receive minimum-sized ethernet frame. Furthermore if multi-buffer would come to play then skb_shared_info stored at the end of XSK frame would be corrupted. HW typically works with 128-aligned sizes so let us provide this value as bare minimum. Multi-buffer setting is known later in the configuration process so besides accounting for 128 bytes, let us also take care of tailroom space upfront.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-43093 since 05/01/2026. The exploitation is known to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 06/24/2026).

The vulnerability scanner Nessus provides a plugin with the ID 322088 (Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2026-1882)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.136, 6.12.83, 6.18.24 or 6.19.14 eliminates this vulnerability. Applying the patch a03975beb9f6af0d8ac051e30b2abeabe618414f/0ec4d3f6e6934deb843b561ae048cd17218e5ad1/9ea6ba4f3195dcba6e8b3e7b2e748593b7cafb12/6523bc1b40e69301f24c14338b762af4739d6d39/a315e022a72d95ef5f1d4e58e903cb492b0ad931 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 (322088) and CERT Bund (WID-SEC-2026-1385). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

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

CNA Base Score: 7.8
CNA Vector (Linux): 🔒

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: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 322088
Nessus Name: Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2026-1882)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.136/6.12.83/6.18.24/6.19.14
Patch: a03975beb9f6af0d8ac051e30b2abeabe618414f/0ec4d3f6e6934deb843b561ae048cd17218e5ad1/9ea6ba4f3195dcba6e8b3e7b2e748593b7cafb12/6523bc1b40e69301f24c14338b762af4739d6d39/a315e022a72d95ef5f1d4e58e903cb492b0ad931

Timelineinfo

05/01/2026 CVE reserved
05/06/2026 +5 days Advisory disclosed
05/06/2026 +0 days VulDB entry created
06/24/2026 +49 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43093 (🔒)
GCVE (CVE): GCVE-0-2026-43093
GCVE (VulDB): GCVE-100-361328
CERT Bund: WID-SEC-2026-1385 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 05/06/2026 12:54
Updated: 06/24/2026 20:35
Changes: 05/06/2026 12:54 (58), 05/07/2026 08:30 (7), 05/20/2026 05:46 (11), 06/08/2026 16:19 (1), 06/24/2026 20:35 (2)
Complete: 🔍
Cache ID: 216::103

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