CVE-2026-18727

Service crash via DHCPv6 length underflow

Published Aug 12, 2026 · Updated Aug 12, 2026

Integer underflow in the iscsiuio DHCPv6 parser in open-iscsi allows remote attackers to crash the process with crafted traffic. A short UDP length makes the parser underflow the computed DHCPv6 payload length, after which it reads beyond the packet boundary. Exploitation requires same-L2 access and an active DHCPv6 exchange, and the established consequence is a process crash or service interruption.

CVSS severity6.5
Medium
EPSS probability0.19%
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 the iscsiuio DHCPv6 parser in open-iscsi allows remote attackers to crash the process with crafted traffic. A short UDP length makes the parser underflow the computed DHCPv6 payload length, after which it reads beyond the packet boundary. Exploitation requires same-L2 access and an active DHCPv6 exchange, and the established consequence is a process crash or service interruption.

The record

CVE
CVE-2026-18727
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-191, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 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 vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5Red HatCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.3Amazon LinuxCVSS:3.1/AV:A/AC:H/PR:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

CWE-191Integer Underflow (Wrap or Wraparound)
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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