Linux Kernel: Out-of-Bounds Access (CVE-2026-98807)
Published Last modified Sources: Debian LTS, BSI, Msrc Update Guide, CVE.org
What is affected, what to do
Update Linux Kernel to version 6.12.113, Linux Kernel to version 6.18.56, Linux Kernel to version 7.2.10.
- Affected
- Linux Kernel
lt 5.18..6.12.113 - Linux Kernel
lt 6.13..6.18.56 - Linux Kernel
lt 6.19..7.2.10
- Linux Kernel
- Fixed in
- Linux Kernel
6.12.113 - Linux Kernel
6.18.56 - Linux Kernel
7.2.10 - Linux Kernel
7.3
- Linux Kernel
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Metrics
3.4
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
3.4
CVSS v3
Severity Low on the scale from 0 to 10.
Source: Debian LTS, BSI, Msrc Update Guide, CVE.org
0.2 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 7.0
Show all metrics
- Severity
- Low
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- 47.39 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- 3.4 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- 3.4
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- 0.2 %
- 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- 7.0
- 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/mlx5: Fix slab-out-of-bounds when handling team device events
The mlx5_handle_changeupper_event() and mlx5_handle_changeinfodata_event() functions check for LAG masters (which includes both bonding and team devices) but only call bonding-specific APIs. When processing team device events, calling bond_slave_get_rcu() and bond_is_slave_inactive() on team_port structures causes KASAN to detect an out-of-bounds memory access since team_port is smaller than bond slave.
Fix this by wrapping the bond-specific API calls with a check for bonding devices. This allows the function to still process LAG events for both bonding and teams but only calls bond-specific functions when dealing with actual bonding devices.
For mlx5_handle_changeinfodata_event(), keep the explicit bond check as mlx5 doesn't handle state information for team ports anyway.
Tested with Mellanox ConnectX-5 on Linux 7.2.0-rc6:
- Bonding: PASS (no regressions)
- Team device: PASS (no KASAN errors)
Source: Debian LTS Advisories, BSI WID Portal, BSI CSAF, Microsoft Security Update Guide, cvelistv5, NVD (NIST)
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 |
|
|
Vendors and products
Affected operating systems
| Linux | debian | linux-6.12 | bookworm |
References & sources
- git.kernel.orgstable/c/04c824940d52871c49866a4ac67b504146f7cf35
- git.kernel.orgstable/c/16ca0e79f31ea810346a79dda545ba344ede1d47
- git.kernel.orgstable/c/3a6e67ff267af2053a793825c3b7844741fed461
- git.kernel.orgstable/c/8117cbc504cb01980258d8a8c9be8f57cf0aaceb
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
1 individual change: Affected versions (publisher)
Show the original change
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/2026/98xxx/CVE-2026-98807.json">CVE-2026-98807</a>Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
ReceivedLinux
Description added or changed
New references:Show 6 original changes
Individual changes of this event as published by NVD Type Action Before After Description added —In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Fix slab-out-of-bounds when handling team device events The mlx5_handle_changeupper_event() and mlx5_handle_changeinfodata_event() functions check for LAG masters (which includes both bonding and team devices) but only call bonding-specific APIs. When processing team device events, calling bond_slave_get_rcu() and bond_is_slave_inactive() on team_port structures causes KASAN to detect an out-of-bounds memory access since team_port is smaller than bond slave. Fix this by wrapping the bond-specific API calls with a check for bonding devices. This allows the function to still process LAG events for both bonding and teams but only calls bond-specific functions when dealing with actual bonding devices. For mlx5_handle_changeinfodata_event(), keep the explicit bond check as mlx5 doesn't handle state information for team ports anyway. Tested with Mellanox ConnectX-5 on Linux 7.2.0-rc6: - Bonding: PASS (no regressions) - Team device: PASS (no KASAN errors)Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98807.json">CVE-2026-98807</a>Reference added —https://git.kernel.org/stable/c/04c824940d52871c49866a4ac67b504146f7cf35Reference added —https://git.kernel.org/stable/c/16ca0e79f31ea810346a79dda545ba344ede1d47Reference added —https://git.kernel.org/stable/c/3a6e67ff267af2053a793825c3b7844741fed461Reference added —https://git.kernel.org/stable/c/8117cbc504cb01980258d8a8c9be8f57cf0aacebSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-98807"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-98807.svg?lang=en" alt="CVE-2026-98807 – NEOSEC Intel" height="20"></a>