Vulnerability-Lookup

UBUNTU-CVE-2026-18727 (CVE-2026-18727)

Vulnerability from osv_ubuntu – Published: 2026-08-12 22:17 – Updated: 2026-08-19 11:01 – Source website

Details

A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption.

Severity

6.5 (Medium)


                    
                      CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-18727	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-18727	REPORT
	https://access.redhat.com/security/cve/CVE-2026-18727	REPORT
	https://bugzilla.redhat.com/show_bug.cgi?id=2462956	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "open-iscsi",
            "binary_version": "2.0.873-3ubuntu9"
          },
          {
            "binary_name": "open-iscsi-utils",
            "binary_version": "2.0.873-3ubuntu9"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:14.04:LTS",
        "name": "open-iscsi",
        "purl": "pkg:deb/ubuntu/open-iscsi@2.0.873-3ubuntu9?arch=source\u0026distro=trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.873-3ubuntu7",
        "2.0.873-3ubuntu8",
        "2.0.873-3ubuntu9"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "open-iscsi",
            "binary_version": "2.0.873+git0.3b4b4500-14ubuntu3.7+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "open-iscsi",
        "purl": "pkg:deb/ubuntu/open-iscsi@2.0.873+git0.3b4b4500-14ubuntu3.7+esm1?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
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            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.873-3ubuntu13",
        "2.0.873+git0.3b4b4500-13ubuntu3",
        "2.0.873+git0.3b4b4500-14ubuntu1",
        "2.0.873+git0.3b4b4500-14ubuntu3",
        "2.0.873+git0.3b4b4500-14ubuntu3.1",
        "2.0.873+git0.3b4b4500-14ubuntu3.2",
        "2.0.873+git0.3b4b4500-14ubuntu3.3",
        "2.0.873+git0.3b4b4500-14ubuntu3.4",
        "2.0.873+git0.3b4b4500-14ubuntu3.5",
        "2.0.873+git0.3b4b4500-14ubuntu3.6",
        "2.0.873+git0.3b4b4500-14ubuntu3.7",
        "2.0.873+git0.3b4b4500-14ubuntu3.7+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "iscsiuio",
            "binary_version": "2.0.874-5ubuntu2.11+esm1"
          },
          {
            "binary_name": "open-iscsi",
            "binary_version": "2.0.874-5ubuntu2.11+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "open-iscsi",
        "purl": "pkg:deb/ubuntu/open-iscsi@2.0.874-5ubuntu2.11+esm1?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.874-4ubuntu3",
        "2.0.874-4ubuntu4",
        "2.0.874-4ubuntu5",
        "2.0.874-5ubuntu1",
        "2.0.874-5ubuntu2",
        "2.0.874-5ubuntu2.1",
        "2.0.874-5ubuntu2.2",
        "2.0.874-5ubuntu2.3",
        "2.0.874-5ubuntu2.4",
        "2.0.874-5ubuntu2.6",
        "2.0.874-5ubuntu2.7",
        "2.0.874-5ubuntu2.9",
        "2.0.874-5ubuntu2.10",
        "2.0.874-5ubuntu2.11",
        "2.0.874-5ubuntu2.11+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "iscsiuio",
            "binary_version": "2.0.874-7.1ubuntu6.5"
          },
          {
            "binary_name": "open-iscsi",
            "binary_version": "2.0.874-7.1ubuntu6.5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "open-iscsi",
        "purl": "pkg:deb/ubuntu/open-iscsi@2.0.874-7.1ubuntu6.5?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
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        "2.0.874-7.1ubuntu5",
        "2.0.874-7.1ubuntu6",
        "2.0.874-7.1ubuntu6.1",
        "2.0.874-7.1ubuntu6.2",
        "2.0.874-7.1ubuntu6.3",
        "2.0.874-7.1ubuntu6.4",
        "2.0.874-7.1ubuntu6.5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "iscsiuio",
            "binary_version": "2.1.5-1ubuntu1.1"
          },
          {
            "binary_name": "libopeniscsiusr",
            "binary_version": "2.1.5-1ubuntu1.1"
          },
          {
            "binary_name": "libopeniscsiusr0.2.0",
            "binary_version": "2.1.5-1ubuntu1.1"
          },
          {
            "binary_name": "open-iscsi",
            "binary_version": "2.1.5-1ubuntu1.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "open-iscsi",
        "purl": "pkg:deb/ubuntu/open-iscsi@2.1.5-1ubuntu1.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
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          ],
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      "versions": [
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        "2.1.4-0ubuntu2",
        "2.1.4-0ubuntu3",
        "2.1.4-0ubuntu4",
        "2.1.5-1ubuntu1",
        "2.1.5-1ubuntu1.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "iscsiuio",
            "binary_version": "2.1.9-3ubuntu5.4"
          },
          {
            "binary_name": "libopeniscsiusr",
            "binary_version": "2.1.9-3ubuntu5.4"
          },
          {
            "binary_name": "open-iscsi",
            "binary_version": "2.1.9-3ubuntu5.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "open-iscsi",
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      },
      "ranges": [
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              "introduced": "0"
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          "type": "ECOSYSTEM"
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      "versions": [
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        "2.1.9-3ubuntu1",
        "2.1.9-3ubuntu2",
        "2.1.9-3ubuntu3",
        "2.1.9-3ubuntu4",
        "2.1.9-3ubuntu5.1",
        "2.1.9-3ubuntu5.2",
        "2.1.9-3ubuntu5.3",
        "2.1.9-3ubuntu5.4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "iscsiuio",
            "binary_version": "2.1.11-3ubuntu3"
          },
          {
            "binary_name": "libopeniscsiusr",
            "binary_version": "2.1.11-3ubuntu3"
          },
          {
            "binary_name": "open-iscsi",
            "binary_version": "2.1.11-3ubuntu3"
          }
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      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "open-iscsi",
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      },
      "ranges": [
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        "2.1.11-3ubuntu1",
        "2.1.11-3ubuntu2",
        "2.1.11-3ubuntu3"
      ]
    }
  ],
  "aliases": [],
  "details": "A flaw was found in open-iscsi\u0027s iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption.",
  "id": "UBUNTU-CVE-2026-18727",
  "modified": "2026-08-19T11:01:27Z",
  "published": "2026-08-12T22:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-18727"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-18727"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2026-18727"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2462956"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-18727"
  ]
}

CVE-2026-18727 (GCVE-0-2026-18727)

Vulnerability from cvelistv5 – Published: 2026-08-12 21:13 – Updated: 2026-08-18 14:37

Title

Open-iscsi: open-iscsi: integer underflow in iscsiuio dhcpv6 parsing

Summary

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-13 19:21 UTC

CWE

CWE-191 - Integer Underflow (Wrap or Wraparound)

Assigner

redhat redhat root

References

2 references

URL	Tags
https://access.redhat.com/security/cve/CVE-2026-18727	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2462956	issue-trackingx_refsource_REDHAT

Impacted products

2 products

Vendor	Product	Version
Red Hat	Red Hat Enterprise Linux 10	cpe:/o:redhat:enterprise_linux:10
Red Hat	Red Hat Enterprise Linux 9	cpe:/o:redhat:enterprise_linux:9

Date Public

2026-08-12 18:05

Credits

This issue was discovered by In partnership with Red Hat (Aisle.com) and Keith Linneman (Linneman Labs).

Show details on NVD website

JSON

To clipboard

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                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-13T19:21:57.942926Z",
                "version": "2.0.3"
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.