Host crash via uninitialized TAP device pointer
Published Aug 22, 2026 · Updated Aug 25, 2026
NULL pointer dereference in the Linux kernel allows guest OS users to crash a virtualization host via crafted virtio-net TX data. tap_get_user_xdp parses a GSO virtio-net header before assigning skb->dev, letting a zero protocol reach dev_parse_header_protocol with a NULL device pointer. Exploitation requires a guest using a vhost-net TAP or macvtap backend with TX batching; the demonstrated consequence is a host kernel panic and interruption of co-resident guests.
Summary
What happened
NULL pointer dereference in the Linux kernel allows guest OS users to crash a virtualization host via crafted virtio-net TX data. tap_get_user_xdp parses a GSO virtio-net header before assigning skb->dev, letting a zero protocol reach dev_parse_header_protocol with a NULL device pointer. Exploitation requires a guest using a vhost-net TAP or macvtap backend with TX batching; the demonstrated consequence is a host kernel panic and interruption of co-resident guests.
The record
- CVE
- CVE-2026-74684
- Published
- Aug 22, 2026
- Updated
- Aug 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 22, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.14.226 <4.15
- Affected versionversion=4.19.181 <4.20
- Affected versionversion=5.10.24 <5.11
- Affected versionversion=5.11.7 <5.12
- Affected versionversion=5.12
- Affected versionversion=5.4.106 <5.5
- Affected versionversion=54ef8243c3c8e90f1ea5792e6752e021a25c8eb3
- Affected versionversion=924a9bc362a5223cd448ca08c3dde21235adc310 <15583b07fd691a844fbf7b3ad612cdc9e9a657c0
- Affected versionversion=924a9bc362a5223cd448ca08c3dde21235adc310 <164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b
- Affected versionversion=924a9bc362a5223cd448ca08c3dde21235adc310 <3874892dd27d5387aa9a06f58d9060f18f351d24
- Affected versionversion=924a9bc362a5223cd448ca08c3dde21235adc310 <8b444b126cd8e4473e652f529753ed4dd1360a9c
- Affected versionversion=99b1d3f74b9ef72c2f74c8e4c078e1bc0706e748
- Affected versionversion=ca278267d6cd9544645731732455b6b20cb0e895
- Affected versionversion=ea3fb2ce5fa794d02135f5c079e05cd6fc3f545d
- Affected versionversion=faa3baa2828c5e1c4374f3e60041f75c64f5fcb6
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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