Linux Kernel: security vulnerability (CVE-2026-23365)
Published Last modified Sources: Siemens ProductCERT, Debian LTS, Debian, SUSE, Ubuntu, BSI, CVE.org, Msrc Update Guide, EUVD
What is affected, what to do
In the Linux kernel, the following vulnerability has been resolved: net: usb: kalmia: validate USB endpoints The kalmia driver should validate that the device it is probing has the proper number and types of USB endpoints it is expecting before it binds to it. If a malicious device were to not have the same urbs the driver will crash later on when it blindly accesses these endpoints.
Update Linux Kernel to version 5.10.253, Linux Kernel to version 5.15.203, Linux Kernel to version 6.1.167.
- Affected
- Linux Kernel
lt 3.0..5.10.253 - Linux Kernel
lt 5.11..5.15.203 - Linux Kernel
lt 5.16..6.1.167 - Linux Kernel
lt 6.2..6.6.130 - Linux Kernel
lt 6.7..6.12.77 - Linux Kernel
lt 6.13..6.18.17 - Linux Kernel
lt 6.19..6.19.7 - Linux Kernel
lt 6.20..7.0
- Linux Kernel
- Fixed in
- Linux Kernel
5.10.253 - Linux Kernel
5.15.203 - Linux Kernel
6.1.167 - Linux Kernel
6.6.130 - Linux Kernel
6.12.77 - Linux Kernel
6.18.17 - Linux Kernel
6.19.7 - Linux Kernel
7.0
- Linux Kernel
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Metrics
5.5
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
5.5
CVSS v3
Severity Medium on the scale from 0 to 10.
Source: Siemens ProductCERT, Debian LTS, Debian, SUSE, Ubuntu, BSI, CVE.org, Msrc Update Guide, EUVD
0.1 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 2.9
Show all metrics
- Severity
- Medium
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 42.99 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 5.5 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 5.5
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.1 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 2.9
- Low — this CVE sits in the lower 10% of all CVEs scored today.
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
In the Linux kernel, the following vulnerability has been resolved: net: usb: kalmia: validate USB endpoints The kalmia driver should validate that the device it is probing has the proper number and types of USB endpoints it is expecting before it binds to it. If a malicious device were to not have the same urbs the driver will crash later on when it blindly accesses these endpoints.
Source: siemens_advisory, Debian LTS Advisories, Debian Security Advisories, suse_csaf, Ubuntu Security Notices, BSI WID Portal, BSI CSAF, cvelistv5, Microsoft Security Update Guide, NVD (NIST), CVE.org (MITRE), ENISA EUVD
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Linux | Linux |
|
|
| Siemens | SIMATIC S7 |
|
|
Vendors and products
Affected operating systems
| Linux | debian | linux | bookworm |
| Linux | debian | linux | bullseye |
| Linux | debian | linux | trixie |
| Linux | debian | linux-6.1 | bullseye |
| Linux | linux | linux_kernel | 3.0 |
| Linux | linux | linux_kernel | 7.0 |
| Linux | linux | linux_kernel | — |
References & sources
- git.kernel.orgstable/c/ff675bc5b3e8c356f9d993d65d0bae6ed0dc7459
- git.kernel.orgstable/c/185050b47df3d41e49f20ad01beea2e7b9cddaa7
- git.kernel.orgstable/c/28a380bfa5bc7f6a9380b85e8eab919ee6ac1701
- git.kernel.orgstable/c/12c0243de0aee0ab27cc00932fd5edae65c1e3a2
- git.kernel.orgstable/c/51c20ea5f1555a984c041b0dbf56f00d41b9e652
- git.kernel.orgstable/c/011684cd18349aa4c52167c8ac37a0524169f48c
- git.kernel.orgstable/c/7bfda1a0be4caec3263753d567678451cef73a85
- git.kernel.orgstable/c/c58b6c29a4c9b8125e8ad3bca0637e00b71e2693
- Siemens ProductCERTproductcert/html/ssa-082556.html
- Siemens ProductCERTproductcert/html/ssa-019113.html
- Siemens ProductCERTproductcert/html/ssa-457936.html
- Siemens ProductCERTproductcert/html/ssa-784472.html
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedLinux
New references:- https://git.kernel.org/stable/c/011684cd18349aa4c52167c8ac37a0524169f48c
- https://git.kernel.org/stable/c/12c0243de0aee0ab27cc00932fd5edae65c1e3a2
- https://git.kernel.org/stable/c/185050b47df3d41e49f20ad01beea2e7b9cddaa7
- https://git.kernel.org/stable/c/28a380bfa5bc7f6a9380b85e8eab919ee6ac1701
and 4 more references
Show 24 original changes
Individual changes of this event as published by NVD Type Action Before After Reference added —https://git.kernel.org/stable/c/011684cd18349aa4c52167c8ac37a0524169f48cReference added —https://git.kernel.org/stable/c/12c0243de0aee0ab27cc00932fd5edae65c1e3a2Reference added —https://git.kernel.org/stable/c/185050b47df3d41e49f20ad01beea2e7b9cddaa7Reference added —https://git.kernel.org/stable/c/28a380bfa5bc7f6a9380b85e8eab919ee6ac1701Reference added —https://git.kernel.org/stable/c/51c20ea5f1555a984c041b0dbf56f00d41b9e652Reference added —https://git.kernel.org/stable/c/7bfda1a0be4caec3263753d567678451cef73a85Reference added —https://git.kernel.org/stable/c/c58b6c29a4c9b8125e8ad3bca0637e00b71e2693Reference added —https://git.kernel.org/stable/c/ff675bc5b3e8c356f9d993d65d0bae6ed0dc7459Reference removed https://git.kernel.org/stable/c/011684cd18349aa4c52167c8ac37a0524169f48c—Reference removed https://git.kernel.org/stable/c/12c0243de0aee0ab27cc00932fd5edae65c1e3a2—Reference removed https://git.kernel.org/stable/c/185050b47df3d41e49f20ad01beea2e7b9cddaa7—Reference removed https://git.kernel.org/stable/c/28a380bfa5bc7f6a9380b85e8eab919ee6ac1701—Reference removed https://git.kernel.org/stable/c/51c20ea5f1555a984c041b0dbf56f00d41b9e652—Reference removed https://git.kernel.org/stable/c/7bfda1a0be4caec3263753d567678451cef73a85—Reference removed https://git.kernel.org/stable/c/c58b6c29a4c9b8125e8ad3bca0637e00b71e2693—Reference removed https://git.kernel.org/stable/c/ff675bc5b3e8c356f9d993d65d0bae6ed0dc7459—Reference type removed https://git.kernel.org/stable/c/011684cd18349aa4c52167c8ac37a0524169f48c Types: Patch—Reference type removed https://git.kernel.org/stable/c/12c0243de0aee0ab27cc00932fd5edae65c1e3a2 Types: Patch—Reference type removed https://git.kernel.org/stable/c/185050b47df3d41e49f20ad01beea2e7b9cddaa7 Types: Patch—Reference type removed https://git.kernel.org/stable/c/28a380bfa5bc7f6a9380b85e8eab919ee6ac1701 Types: Patch—Reference type removed https://git.kernel.org/stable/c/51c20ea5f1555a984c041b0dbf56f00d41b9e652 Types: Patch—Reference type removed https://git.kernel.org/stable/c/7bfda1a0be4caec3263753d567678451cef73a85 Types: Patch—Reference type removed https://git.kernel.org/stable/c/c58b6c29a4c9b8125e8ad3bca0637e00b71e2693 Types: Patch—Reference type removed https://git.kernel.org/stable/c/ff675bc5b3e8c356f9d993d65d0bae6ed0dc7459 Types: Patch—Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Record modifiedSiemens ADP
Show 7 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/23xxx/CVE-2026-23365.json">CVE-2026-23365</a>Reference added —https://cert-portal.siemens.com/productcert/html/ssa-019113.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-082556.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-457936.htmlReference added —https://cert-portal.siemens.com/productcert/html/ssa-784472.htmlReference removed https://cert-portal.siemens.com/productcert/html/ssa-019113.html—Reference removed https://cert-portal.siemens.com/productcert/html/ssa-082556.html—Source identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-23365"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-23365.svg?lang=en" alt="CVE-2026-23365 – NEOSEC Intel" height="20"></a>