CVE-2025-38432

IPv6 netpoll failure via uninitialized UDP checksum

Published Jul 25, 2025 · Updated May 11, 2026

Incorrect checksum handling in Linux kernel 6.15 through 6.15.4 allows local users to disrupt IPv6 netpoll transmission. In net/core/netpoll.c, netpoll_send_udp passes an uninitialized UDP check field into csum_ipv6_magic, producing invalid checksums for IPv6 packets. The affected path requires configured IPv6 netpoll use, and the bounded consequence is failed netpoll packet delivery, including lost netconsole logging, rather than general kernel failure.

CVSS severity5.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect checksum handling in Linux kernel 6.15 through 6.15.4 allows local users to disrupt IPv6 netpoll transmission. In net/core/netpoll.c, netpoll_send_udp passes an uninitialized UDP check field into csum_ipv6_magic, producing invalid checksums for IPv6 packets. The affected path requires configured IPv6 netpoll use, and the bounded consequence is failed netpoll packet delivery, including lost netconsole logging, rather than general kernel failure.

The record

CVE
CVE-2025-38432
Published
Jul 25, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 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=6.15
  2. Affected versionversion=f1fce08e63fe1a2a8b8106b93b7244a39830edae <353016ec159f939a380ff6746476a779367ba9a3
  3. Affected versionversion=f1fce08e63fe1a2a8b8106b93b7244a39830edae <f5990207026987a353d5a95204c4d9cb725637fd

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.15; version=f1fce08e63fe1a2a8b8106b93b7244a39830edae <353016ec159f939a380ff6746476a779367ba9a3; version=f1fce08e63fe1a2a8b8106b93b7244a39830edae <f5990207026987a353d5a95204c4d9cb725637fd

Published CVSS scores

5.5NIST NVDCVSS: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

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

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
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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