CVE-2026-98631Public exploitHinoki check available

Kernel crash via sign-extended bounds comparison

Published Oct 18, 2026 · Updated Oct 18, 2026

Out-of-bounds reads in Linux XSK map lookup allow local users to crash the kernel through a crafted BPF map and program. In net/xdp/xskmap.c, xsk_map_gen_lookup() generates a 64-bit comparison whose sign-extended max_entries immediate lets an invalid index bypass the array bounds check. The demonstrated trigger requires root access and enough memory for a large map; the reported consequence is a kernel panic, not demonstrated data disclosure or privilege escalation.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Out-of-bounds reads in Linux XSK map lookup allow local users to crash the kernel through a crafted BPF map and program. In net/xdp/xskmap.c, xsk_map_gen_lookup() generates a 64-bit comparison whose sign-extended max_entries immediate lets an invalid index bypass the array bounds check. The demonstrated trigger requires root access and enough memory for a large map; the reported consequence is a kernel panic, not demonstrated data disclosure or privilege escalation.

The record

CVE
CVE-2026-98631
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 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=5.5
  2. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <11d9be35c1f4233798e99be98bc474f83a254c6c
  3. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <123f90f394ca404ab8796a7c8072ff7fa5b65a9c
  4. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <227ec890559e922e235eb543646e3bf0bd8269b0
  5. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <36461e58f88a1b723f86693f437ac12e60ff4363
  6. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <3c1e0a4bc156b8d5c5772dbc76b9ea74dce5ca24
  7. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <70504de0bb627848667207bec7ccfd647deb8814
  8. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <b5c0cff0c5331582ab01c4c423731453a8381acc
  9. Affected versionversion=e65650f291ee72fc578d6346080fc4699204ef2c <c6d5c582d55a8f229d75e98d62eaa065b0deb18d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=e65650f291ee72fc578d6346080fc4699204ef2c <11d9be35c1f4233798e99be98bc474f83a254c6c; version=e65650f291ee72fc578d6346080fc4699204ef2c <123f90f394ca404ab8796a7c8072ff7fa5b65a9c; version=e65650f291ee72fc578d6346080fc4699204ef2c <227ec890559e922e235eb543646e3bf0bd8269b0; version=e65650f291ee72fc578d6346080fc4699204ef2c <36461e58f88a1b723f86693f437ac12e60ff4363; version=e65650f291ee72fc578d6346080fc4699204ef2c <3c1e0a4bc156b8d5c5772dbc76b9ea74dce5ca24; version=e65650f291ee72fc578d6346080fc4699204ef2c <70504de0bb627848667207bec7ccfd647deb8814; version=e65650f291ee72fc578d6346080fc4699204ef2c <b5c0cff0c5331582ab01c4c423731453a8381acc; version=e65650f291ee72fc578d6346080fc4699204ef2c <c6d5c582d55a8f229d75e98d62eaa065b0deb18d

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

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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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

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

Technologies

Your stack

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