CVE-2026-43032

Kernel crash via unbounded UART receive buffer

Published May 1, 2026 · Updated May 1, 2026

Out-of-bounds write in the Linux Kernel PN533 UART driver allows local users to crash the system through malformed UART input. pn532_receive_buf() appends each byte to dev->recv_skb but clears the partial frame only after a valid header, so headerless traffic exhausts tailroom before skb_put_u8() writes another byte. Exploitation requires local access to supply UART traffic to an active PN533-compatible NFC device; the documented impact is a kernel crash without confidentiality or integrity loss.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in the Linux Kernel PN533 UART driver allows local users to crash the system through malformed UART input. pn532_receive_buf() appends each byte to dev->recv_skb but clears the partial frame only after a valid header, so headerless traffic exhausts tailroom before skb_put_u8() writes another byte. Exploitation requires local access to supply UART traffic to an active PN533-compatible NFC device; the documented impact is a kernel crash without confidentiality or integrity loss.

The record

CVE
CVE-2026-43032
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <23e925183db26cd322597679669ad29d70ed2ada
  3. Affected versionversion=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <2c1fadd221b21d8038acfe6a0f56291881d5ff76
  4. Affected versionversion=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <30fe3f5f6494f827d812ff179f295a8e532709d6
  5. Affected versionversion=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <3adca9be14bf36b927193f05f5aea35a1a90e913
  6. Affected versionversion=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <8bedf1dd5640ac8997bff00bbefe241b438df397
  7. Affected versionversion=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <ad2f60de5045bfb5d20ea468a97c8760c6a3a4f8
  8. Affected versionversion=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <cf2ff10183204349edfd6b972e189375fc5f1fb0
  9. Affected versionversion=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <f48ab6ee654ecc350434e4566bc785773f412b7e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.5; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <23e925183db26cd322597679669ad29d70ed2ada; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <2c1fadd221b21d8038acfe6a0f56291881d5ff76; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <30fe3f5f6494f827d812ff179f295a8e532709d6; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <3adca9be14bf36b927193f05f5aea35a1a90e913; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <8bedf1dd5640ac8997bff00bbefe241b438df397; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <ad2f60de5045bfb5d20ea468a97c8760c6a3a4f8; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <cf2ff10183204349edfd6b972e189375fc5f1fb0; version=c656aa4c27b17a8c70da223ed5ab42145800d6b5 <f48ab6ee654ecc350434e4566bc785773f412b7e

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 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

T1499.004Application or System Exploitation

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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