CVE-2026-37534Network attack vector

Arbitrary memory write via underflowed sequence index

Published May 1, 2026 · Updated May 1, 2026

Integer underflow in Open-SAE-J1939 allows attackers to write arbitrary memory through a crafted CAN frame sequence number. SAE_J1939_Read_Transport_Protocol_Data_Transfer subtracts one from the unvalidated sequence byte, so zero wraps the index before seven payload bytes are copied out of bounds. The attacker must deliver a malicious J1939 transport data-transfer frame over a reachable network path or directly on the CAN bus.

CVSS severity9.8
Critical
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Open-SAE-J1939 allows attackers to write arbitrary memory through a crafted CAN frame sequence number. SAE_J1939_Read_Transport_Protocol_Data_Transfer subtracts one from the unvalidated sequence byte, so zero wraps the index before seven payload bytes are copied out of bounds. The attacker must deliver a malicious J1939 transport data-transfer frame over a reachable network path or directly on the CAN bus.

The record

CVE
CVE-2026-37534
Published
May 1, 2026
Updated
May 1, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-191, T0866
Attack vector
network
Privileges
unauthenticated

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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T0866Exploitation of Remote Services

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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