CVE-2025-21997

Service interruption via XSK buffer aliasing

Published Apr 3, 2025 · Updated May 11, 2026

Integer overflow in Linux kernel XSK buffer pools from 5.16 allows local users to interrupt service through crafted UMEM geometry. In xp_create_and_assign_umem(), multiplying two u32 values before conversion to u64 can wrap, assigning distinct XDP buffers to the same memory. Low-privileged local access is required; published assessments identify availability impact but do not specify whether failure causes a hang, crash, or reboot.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Linux kernel XSK buffer pools from 5.16 allows local users to interrupt service through crafted UMEM geometry. In xp_create_and_assign_umem(), multiplying two u32 values before conversion to u64 can wrap, assigning distinct XDP buffers to the same memory. Low-privileged local access is required; published assessments identify availability impact but do not specify whether failure causes a hang, crash, or reboot.

The record

CVE
CVE-2025-21997
Published
Apr 3, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-190, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 3, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=5.16
  2. Affected versionversion=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <130290f44bce0eead2b827302109afc3fe189ddd
  3. Affected versionversion=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <205649d642a5b376724f04f3a5b3586815e43d3b
  4. Affected versionversion=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <559847f56769037e5b2e0474d3dbff985b98083d
  5. Affected versionversion=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <b7b4be1fa43294b50b22e812715198629806678a
  6. Affected versionversion=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <c7670c197b0f1a8726ad5c87bc2bf001a1fc1bbd

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.16; version=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <130290f44bce0eead2b827302109afc3fe189ddd; version=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <205649d642a5b376724f04f3a5b3586815e43d3b; version=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <559847f56769037e5b2e0474d3dbff985b98083d; version=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <b7b4be1fa43294b50b22e812715198629806678a; version=94033cd8e73b8632bab7c8b7bb54caa4f5616db7 <c7670c197b0f1a8726ad5c87bc2bf001a1fc1bbd

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.1OracleCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1499Endpoint Denial of Service

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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