Linux Kernel: Denial of Service (CVE-2026-98878)
Published Last modified Sources: Msrc Update Guide, CVE.org, BSI
What is affected, what to do
In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v5: Immediately exec priority drop following activate With GICv5 an interrupt of equal or lower priority cannot be signalled until there has been a priority drop. This is done via the GIC CDEOI system instruction.
Update Linux Kernel to version 6.18.53, Linux Kernel to version 7.2.
- Affected
- Linux Kernel
lt 6.17..6.18.53 - Linux Kernel
lt 6.19..7.2
- Linux Kernel
- Fixed in
- Linux Kernel
6.18.53 - Linux Kernel
7.2
- Linux Kernel
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Metrics
5.5
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
5.5
CVSS v3
Severity Medium on the scale from 0 to 10.
Source: Msrc Update Guide, CVE.org, BSI
0.2 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 8.9
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- 58.13 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- 0.2 %
- 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- 8.9
- 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: irqchip/gic-v5: Immediately exec priority drop following activate With GICv5 an interrupt of equal or lower priority cannot be signalled until there has been a priority drop. This is done via the GIC CDEOI system instruction. Once this has been executed, the hardware is able to signal the next interrupt if there is one. As all interrupts are programmed to have the same priority, no new interrupts can be signalled until the priority drop has happened. This can cause issues when, for example, an interrupt remains active while a long running process takes place, such as when injecting a physical interrupt into a guest VM in software. The GICv5 driver has so far done the priority drop as part of irq_eoi(), i.e., at the same time as deactivating the interrupt. This means that any long running process (or VM) could block incoming interrupts, effectively causing a denial of service for all other interrupts. Rather than doing the EOI as part of irq_eoi() (which the name would suggest would be a good place for it), move it to happen immediately after acknowledging an interrupt in the main GICv5 interrupt handler. The deactivation of interrupts (GIC CDDI) remains implemented as part of irq_eoi(), which means that the same interrupt cannot be signalled a second time until deactivated by software.
Source: Microsoft Security Update Guide, cvelistv5, NVD (NIST), BSI CSAF, BSI WID Portal
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 |
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Vendors and products
References & sources
- git.kernel.orgstable/c/abf60331ebe9a9a7937a72aac7699c2907ab9307
- git.kernel.orgstable/c/c29bb5acd0cad0b49399d1399dd1bacb39e41438
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).
ReceivedLinux
Description added or changed
Show 4 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: irqchip/gic-v5: Immediately exec priority drop following activate With GICv5 an interrupt of equal or lower priority cannot be signalled until there has been a priority drop. This is done via the GIC CDEOI system instruction. Once this has been executed, the hardware is able to signal the next interrupt if there is one. As all interrupts are programmed to have the same priority, no new interrupts can be signalled until the priority drop has happened. This can cause issues when, for example, an interrupt remains active while a long running process takes place, such as when injecting a physical interrupt into a guest VM in software. The GICv5 driver has so far done the priority drop as part of irq_eoi(), i.e., at the same time as deactivating the interrupt. This means that any long running process (or VM) could block incoming interrupts, effectively causing a denial of service for all other interrupts. Rather than doing the EOI as part of irq_eoi() (which the name would suggest would be a good place for it), move it to happen immediately after acknowledging an interrupt in the main GICv5 interrupt handler. The deactivation of interrupts (GIC CDDI) remains implemented as part of irq_eoi(), which means that the same interrupt cannot be signalled a second time until deactivated by software.Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98878.json">CVE-2026-98878</a>Reference added —https://git.kernel.org/stable/c/abf60331ebe9a9a7937a72aac7699c2907ab9307Reference added —https://git.kernel.org/stable/c/c29bb5acd0cad0b49399d1399dd1bacb39e41438Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-98878"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-98878.svg?lang=en" alt="CVE-2026-98878 – NEOSEC Intel" height="20"></a>