Vulnerability-Lookup

UBUNTU-CVE-2026-18726 (CVE-2026-18726)

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. This vulnerability allows a remote attacker on the same local network segment to cause a Denial of Service (DoS) in the iscsiuio daemon. By sending a specially crafted Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement with a zero-length option, the attacker can trigger an infinite loop. This leads to sustained CPU usage, rendering the daemon unresponsive and impacting system availability. A secondary risk of out-of-bounds reads exists with a short IPv6 payload, though no memory corruption or data exposure has been confirmed.

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-2026-18726	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-18726	REPORT
	https://access.redhat.com/security/cve/CVE-2026-18726	REPORT
	https://bugzilla.redhat.com/show_bug.cgi?id=2462331	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": [
            {
              "introduced": "0"
            }
          ],
          "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": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.874-7.1ubuntu3",
        "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": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.1.4-0ubuntu1",
        "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",
        "purl": "pkg:deb/ubuntu/open-iscsi@2.1.9-3ubuntu5.4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.1.8-1ubuntu2",
        "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"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "open-iscsi",
        "purl": "pkg:deb/ubuntu/open-iscsi@2.1.11-3ubuntu3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.1.11-1ubuntu3",
        "2.1.11-3ubuntu1",
        "2.1.11-3ubuntu2",
        "2.1.11-3ubuntu3"
      ]
    }
  ],
  "aliases": [],
  "details": "A flaw was found in open-iscsi. This vulnerability allows a remote attacker on the same local network segment to cause a Denial of Service (DoS) in the iscsiuio daemon. By sending a specially crafted Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement with a zero-length option, the attacker can trigger an infinite loop. This leads to sustained CPU usage, rendering the daemon unresponsive and impacting system availability. A secondary risk of out-of-bounds reads exists with a short IPv6 payload, though no memory corruption or data exposure has been confirmed.",
  "id": "UBUNTU-CVE-2026-18726",
  "modified": "2026-08-19T11:01:27Z",
  "published": "2026-08-12T22:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-18726"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-18726"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2026-18726"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2462331"
    }
  ],
  "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-2026-18726"
  ]
}

CVE-2026-18726 (GCVE-0-2026-18726)

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

Title

Open-iscsi: open-iscsi: denial of service in iscsiuio router advertisement 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 13:42 UTC

CWE

CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Assigner

redhat redhat root

References

2 references

URL	Tags
https://access.redhat.com/security/cve/CVE-2026-18726	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2462331	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 18:04

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

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-18726",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-13T13:42:48.403070Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-13T13:43:03.014Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
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          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
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          "defaultStatus": "affected",
          "packageName": "iscsi-initiator-utils",
          "product": "Red Hat Enterprise Linux 10",
          "vendor": "Red Hat"
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          "value": "A flaw was found in open-iscsi. This vulnerability allows a remote attacker on the same local network segment to cause a Denial of Service (DoS) in the iscsiuio daemon. By sending a specially crafted Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement with a zero-length option, the attacker can trigger an infinite loop. This leads to sustained CPU usage, rendering the daemon unresponsive and impacting system availability. A secondary risk of out-of-bounds reads exists with a short IPv6 payload, though no memory corruption or data exposure has been confirmed."
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            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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      ],
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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.