Linux Kernel: security vulnerability (CVE-2026-98765)
Published Last modified Sources: Debian LTS, Msrc Update Guide, CVE.org, BSI
What is affected, what to do
In the Linux kernel, the following vulnerability has been resolved: USB: gadget: dummy-hcd: Fix wait for outstanding request completions The dummy-hcd driver emulates synchronize_irq() by waiting until its private callback_usage counter drops to 0 (with the private lock not held). This counter is incremented whenever a gadget driver callback occurs (which requires the private lock to be dropped), but not when a request completion handler is called.
The available sources name no fixed version. Check the vendor guidance in the references below.
Conflicting version data — version display is hidden until the data is resolved.
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Metrics
5.7
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
5.7
CVSS v3
Severity Medium on the scale from 0 to 10.
Source: Debian LTS, Msrc Update Guide, CVE.org, BSI
0.2 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 7.1
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- 58.91 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- 5.7 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- 5.7
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- 7.1
- 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: USB: gadget: dummy-hcd: Fix wait for outstanding request completions The dummy-hcd driver emulates synchronize_irq() by waiting until its private callback_usage counter drops to 0 (with the private lock not held). This counter is incremented whenever a gadget driver callback occurs (which requires the private lock to be dropped), but not when a request completion handler is called. This is an oversight. Request completion is triggered by timer interrupts (emulating device IRQs in a real UDC), and the interrupt handlers are supposed to have completed when the synchronize_irq() emulation routine returns -- they aren't supposed to be in the middle of a completion callback. If this happens it can lead to a gadget driver's unbind routine running before all outstanding request completions have finished, maybe even allowing the gadget driver's module to be unloaded while a completion handler is still running. Fix the oversight by incrementing the callback_usage value across request completion callbacks.
Source: Debian LTS Advisories, Microsoft Security Update Guide, cvelistv5, NVD (NIST), BSI WID Portal, BSI CSAF
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/3070806a7bc7bb36ed04a21022c09dafcc5619f4
- git.kernel.orgstable/c/5298c96bf0068f3160969f7ddad81976d01a9b66
- git.kernel.orgstable/c/7ce4dca0d53b1c3cb2b7e7bb2e42bf5db860caf2
- git.kernel.orgstable/c/b263ff9b0fc5c1f371d65c4eb196b31263d039ff
- git.kernel.orgstable/c/6849e51b89de5b6fc7447dc8e612b58df19c7dea
- git.kernel.orgstable/c/32721319e89a2be610b0518b88f0d188ce878063
- git.kernel.orgstable/c/48ef54100ceffbd1a055f193873574c45f408eb5
- git.kernel.orgstable/c/d77cc7c0d739fb17413714c5c4914bd396502e20
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
Show 4 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/2026/98xxx/CVE-2026-98765.json">CVE-2026-98765</a>Reference added —https://git.kernel.org/stable/c/32721319e89a2be610b0518b88f0d188ce878063Reference added —https://git.kernel.org/stable/c/48ef54100ceffbd1a055f193873574c45f408eb5Reference added —https://git.kernel.org/stable/c/d77cc7c0d739fb17413714c5c4914bd396502e20Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Record modifiedLinux
Show 2 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/2026/98xxx/CVE-2026-98765.json">CVE-2026-98765</a>Reference added —https://git.kernel.org/stable/c/6849e51b89de5b6fc7447dc8e612b58df19c7deaSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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-2026-98765.json">CVE-2026-98765</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: USB: gadget: dummy-hcd: Fix wait for outstanding request completions The dummy-hcd driver emulates synchronize_irq() by waiting until its private callback_usage counter drops to 0 (with the private lock not held). This counter is incremented whenever a gadget driver callback occurs (which requires the private lock to be dropped), but not when a request completion handler is called. This is an oversight. Request completion is triggered by timer interrupts (emulating device IRQs in a real UDC), and the interrupt handlers are supposed to have completed when the synchronize_irq() emulation routine returns -- they aren't supposed to be in the middle of a completion callback. If this happens it can lead to a gadget driver's unbind routine running before all outstanding request completions have finished, maybe even allowing the gadget driver's module to be unloaded while a completion handler is still running. Fix the oversight by incrementing the callback_usage value across request completion callbacks.Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98765.json">CVE-2026-98765</a>Reference added —https://git.kernel.org/stable/c/3070806a7bc7bb36ed04a21022c09dafcc5619f4Reference added —https://git.kernel.org/stable/c/5298c96bf0068f3160969f7ddad81976d01a9b66Reference added —https://git.kernel.org/stable/c/7ce4dca0d53b1c3cb2b7e7bb2e42bf5db860caf2Reference added —https://git.kernel.org/stable/c/b263ff9b0fc5c1f371d65c4eb196b31263d039ffSource identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-98765"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-98765.svg?lang=en" alt="CVE-2026-98765 – NEOSEC Intel" height="20"></a>