Linux Kernel: security vulnerability (CVE-2026-53149)
Published Last modified Sources: SUSE, Debian LTS, Ubuntu, BSI, Siemens ProductCERT, CVE.org, Msrc Update Guide
What is affected, what to do
In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Bound root directory content to block size __tb_property_parse_dir() does not check that content_offset + content_len fits within block_len for the root directory case. When rootdir->length equals or exceeds block_len - 2, the entry loop reads past the allocated property block.
Update Linux Kernel to version 5.10.259, Linux Kernel to version 5.15.210, Linux Kernel to version 6.1.176.
- Affected
- Linux Kernel
lt 4.15..5.10.259 - Linux Kernel
lt 5.11..5.15.210 - Linux Kernel
lt 5.16..6.1.176 - Linux Kernel
lt 6.2..6.6.143 - Linux Kernel
lt 6.7..6.12.94 - Linux Kernel
lt 6.13..6.18.36 - Linux Kernel
lt 6.19..7.0.13
- Linux Kernel
- Fixed in
- Linux Kernel
5.10.259 - Linux Kernel
5.15.210 - Linux Kernel
6.1.176 - Linux Kernel
6.6.143 - Linux Kernel
6.12.94 - Linux Kernel
6.18.36 - Linux Kernel
7.0.13 - Linux Kernel
7.1
- Linux Kernel
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Metrics
7.1
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
7.1
CVSS v3
Severity High on the scale from 0 to 10.
Source: SUSE, Debian LTS, Ubuntu, BSI, Siemens ProductCERT, CVE.org, Msrc Update Guide
0.1 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 2.4
Show all metrics
- Severity
- High
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- 55.07 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- 7.1 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- 7.1
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- 2.4
- 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- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
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: thunderbolt: Bound root directory content to block size __tb_property_parse_dir() does not check that content_offset + content_len fits within block_len for the root directory case. When rootdir->length equals or exceeds block_len - 2, the entry loop reads past the allocated property block. Add a bounds check after computing content_offset and content_len to reject directories whose content extends past the block.
Source: suse_csaf, Debian LTS Advisories, Ubuntu Security Notices, BSI WID Portal, BSI CSAF, siemens_advisory, cvelistv5, NVD (NIST), Microsoft Security Update Guide, CVE.org (MITRE)
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-6.1 | bullseye |
| Linux | ubuntu | linux-oracle-7.0 | noble |
| Linux | linux | linux_kernel | 7.1 |
| Linux | linux | linux_kernel | — |
References & sources
- git.kernel.orgstable/c/5c7657d38d07268124782f03519f07c22a5814fb
- git.kernel.orgstable/c/b212bc161d8a9937b42153723a4a3f2f74fab528
- git.kernel.orgstable/c/1912be23daf4afc8d24ce916021ab68ca4c679db
- git.kernel.orgstable/c/4d0b1524caadb04c10a71f3f88692c63dcb39115
- git.kernel.orgstable/c/0a32040a48db8cf35de48b85d6115df5623e4964
- git.kernel.orgstable/c/60ba6217460792356a238299edd675d91d46bab4
- git.kernel.orgstable/c/cbeb68cbaa0a6f979ef428a7f2d0268c082ba166
- git.kernel.orgstable/c/65423079c7420e3dbf9a7aa345c243a3f5752e5d
- 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/0a32040a48db8cf35de48b85d6115df5623e4964
- https://git.kernel.org/stable/c/1912be23daf4afc8d24ce916021ab68ca4c679db
- https://git.kernel.org/stable/c/4d0b1524caadb04c10a71f3f88692c63dcb39115
- https://git.kernel.org/stable/c/5c7657d38d07268124782f03519f07c22a5814fb
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/0a32040a48db8cf35de48b85d6115df5623e4964Reference added —https://git.kernel.org/stable/c/1912be23daf4afc8d24ce916021ab68ca4c679dbReference added —https://git.kernel.org/stable/c/4d0b1524caadb04c10a71f3f88692c63dcb39115Reference added —https://git.kernel.org/stable/c/5c7657d38d07268124782f03519f07c22a5814fbReference added —https://git.kernel.org/stable/c/60ba6217460792356a238299edd675d91d46bab4Reference added —https://git.kernel.org/stable/c/65423079c7420e3dbf9a7aa345c243a3f5752e5dReference added —https://git.kernel.org/stable/c/b212bc161d8a9937b42153723a4a3f2f74fab528Reference added —https://git.kernel.org/stable/c/cbeb68cbaa0a6f979ef428a7f2d0268c082ba166Reference removed https://git.kernel.org/stable/c/0a32040a48db8cf35de48b85d6115df5623e4964—Reference removed https://git.kernel.org/stable/c/1912be23daf4afc8d24ce916021ab68ca4c679db—Reference removed https://git.kernel.org/stable/c/4d0b1524caadb04c10a71f3f88692c63dcb39115—Reference removed https://git.kernel.org/stable/c/5c7657d38d07268124782f03519f07c22a5814fb—Reference removed https://git.kernel.org/stable/c/60ba6217460792356a238299edd675d91d46bab4—Reference removed https://git.kernel.org/stable/c/65423079c7420e3dbf9a7aa345c243a3f5752e5d—Reference removed https://git.kernel.org/stable/c/b212bc161d8a9937b42153723a4a3f2f74fab528—Reference removed https://git.kernel.org/stable/c/cbeb68cbaa0a6f979ef428a7f2d0268c082ba166—Reference type removed https://git.kernel.org/stable/c/0a32040a48db8cf35de48b85d6115df5623e4964 Types: Patch—Reference type removed https://git.kernel.org/stable/c/1912be23daf4afc8d24ce916021ab68ca4c679db Types: Patch—Reference type removed https://git.kernel.org/stable/c/4d0b1524caadb04c10a71f3f88692c63dcb39115 Types: Patch—Reference type removed https://git.kernel.org/stable/c/5c7657d38d07268124782f03519f07c22a5814fb Types: Patch—Reference type removed https://git.kernel.org/stable/c/60ba6217460792356a238299edd675d91d46bab4 Types: Patch—Reference type removed https://git.kernel.org/stable/c/65423079c7420e3dbf9a7aa345c243a3f5752e5d Types: Patch—Reference type removed https://git.kernel.org/stable/c/b212bc161d8a9937b42153723a4a3f2f74fab528 Types: Patch—Reference type removed https://git.kernel.org/stable/c/cbeb68cbaa0a6f979ef428a7f2d0268c082ba166 Types: Patch—Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Record modifiedSiemens ADP
Show 2 original changes
Individual changes of this event as published by NVD Type Action Before After Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/53xxx/CVE-2026-53149.json">CVE-2026-53149</a>Reference added —https://cert-portal.siemens.com/productcert/html/ssa-784472.htmlSource identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-53149"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-53149.svg?lang=en" alt="CVE-2026-53149 – NEOSEC Intel" height="20"></a>