CVE-2025-40043

Uninitialized kernel-memory access via malformed NCI packets

Published Oct 28, 2025 · Updated Oct 28, 2025

An uninitialized-memory flaw in Linux NFC NCI allows physically proximate attackers to trigger unspecified impact through crafted packets. nic_valid_size compares only the skb length with the embedded NCI header length, so opcode handlers process unassigned skb_buff->data as a valid layout. Reachability requires NFC/NCI packet access; the CNA has not tied the uninitialized reads to a specific crash, disclosure, or code-execution outcome.

CVSS severity8.8
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An uninitialized-memory flaw in Linux NFC NCI allows physically proximate attackers to trigger unspecified impact through crafted packets. nic_valid_size compares only the skb length with the embedded NCI header length, so opcode handlers process unassigned skb_buff->data as a valid layout. Reachability requires NFC/NCI packet access; the CNA has not tied the uninitialized reads to a specific crash, disclosure, or code-execution outcome.

The record

CVE
CVE-2025-40043
Published
Oct 28, 2025
Updated
Oct 28, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2025Record 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=3.2
  2. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <0ba68bea1e356f466ad29449938bea12f5f3711f
  3. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <74837bca0748763a77f77db47a0bdbe63b347628
  4. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <8fcc7315a10a84264e55bb65ede10f0af20a983f
  5. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <9c328f54741bd5465ca1dc717c84c04242fac2e1
  6. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <bfdda0123dde406dbff62e7e9136037e97998a15
  7. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <c395d1e548cc68e84584ffa2e3ca9796a78bf7b9

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.2; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <0ba68bea1e356f466ad29449938bea12f5f3711f; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <74837bca0748763a77f77db47a0bdbe63b347628; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <8fcc7315a10a84264e55bb65ede10f0af20a983f; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <9c328f54741bd5465ca1dc717c84c04242fac2e1; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <bfdda0123dde406dbff62e7e9136037e97998a15; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <c395d1e548cc68e84584ffa2e3ca9796a78bf7b9

Published CVSS scores

8.8kernel.orgCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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)
Vectoradjacent
Privilegesunauthenticated
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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