CVE-2026-63955Network attack vector

Kernel crash via false interrupt-context assertion

Published Jul 19, 2026 · Updated Jul 19, 2026

Denial of service in Linux Kernel 6.19 allows remote attackers to crash the kernel through bridge VLAN processing. The mm/vmalloc __get_vm_area_node function treats every true in_interrupt result as fatal, so bottom-half-disabled bridge allocation reaches BUG_ON outside NMI or hard IRQ context. Network reachability is unauthenticated, and the bounded consequence is a kernel crash with no reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Linux Kernel 6.19 allows remote attackers to crash the kernel through bridge VLAN processing. The mm/vmalloc __get_vm_area_node function treats every true in_interrupt result as fatal, so bottom-half-disabled bridge allocation reaches BUG_ON outside NMI or hard IRQ context. Network reachability is unauthenticated, and the bounded consequence is a kernel crash with no reported data disclosure or modification.

The record

CVE
CVE-2026-63955
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.19
  2. Affected versionversion=c6307674ed82c0c57d6e1e3408e84ac449ab8e94 <04aa71da5f35aacdc9ae9cb5150947daa624f641
  3. Affected versionversion=c6307674ed82c0c57d6e1e3408e84ac449ab8e94 <ad7eff07b625f53c3fb513b30d7a8c5a79fbc7ce

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.19; version=c6307674ed82c0c57d6e1e3408e84ac449ab8e94 <04aa71da5f35aacdc9ae9cb5150947daa624f641; version=c6307674ed82c0c57d6e1e3408e84ac449ab8e94 <ad7eff07b625f53c3fb513b30d7a8c5a79fbc7ce

Published CVSS scores

7.5kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo