CVE-2026-99055

Crash via unchecked TCP fragment page dereference

Published Oct 23, 2026 · Updated Oct 23, 2026

A NULL dereference in Linux 6.12 TCP zerocopy receive allows attackers to crash the kernel via non-page-backed fragments. After a readable prefix, can_map_frag() passes the NULL page returned for a net_iov fragment to PageCompound() while calculating mapping hints. The diagnostic demonstrated panic with panic_on_warn enabled using an injected fragment; hardware end-to-end reachability remains untested and requires CONFIG_NET_DEVMEM plus a supported DMA-buf-bound RX queue.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Nov 1, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A NULL dereference in Linux 6.12 TCP zerocopy receive allows attackers to crash the kernel via non-page-backed fragments. After a readable prefix, can_map_frag() passes the NULL page returned for a net_iov fragment to PageCompound() while calculating mapping hints. The diagnostic demonstrated panic with panic_on_warn enabled using an injected fragment; hardware end-to-end reachability remains untested and requires CONFIG_NET_DEVMEM plus a supported DMA-buf-bound RX queue.

The record

CVE
CVE-2026-99055
Published
Oct 23, 2026
Updated
Oct 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 23, 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.

  1. Affected versionversion=6.12
  2. Affected versionversion=9f6b619edf2e85746f261b42ae8f818a59d126f7 <1c7463ac0e99cc91c4eecc1b69a740ef1a619932
  3. Affected versionversion=9f6b619edf2e85746f261b42ae8f818a59d126f7 <3aa6f536a95eb0617c313ae2eb76fdfa85331f85
  4. Affected versionversion=9f6b619edf2e85746f261b42ae8f818a59d126f7 <563d3564513496b9ce3b3ba7a5154427554d0f06
  5. Affected versionversion=9f6b619edf2e85746f261b42ae8f818a59d126f7 <8b1f0af1fd5fd113432233ed8a3862ee7c30a84f

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.12; version=9f6b619edf2e85746f261b42ae8f818a59d126f7 <1c7463ac0e99cc91c4eecc1b69a740ef1a619932; version=9f6b619edf2e85746f261b42ae8f818a59d126f7 <3aa6f536a95eb0617c313ae2eb76fdfa85331f85; version=9f6b619edf2e85746f261b42ae8f818a59d126f7 <563d3564513496b9ce3b3ba7a5154427554d0f06; version=9f6b619edf2e85746f261b42ae8f818a59d126f7 <8b1f0af1fd5fd113432233ed8a3862ee7c30a84f

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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

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Your stack

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