Vulnerability-Lookup

UBUNTU-CVE-2026-18238 (CVE-2026-18238)

Vulnerability from osv_ubuntu – Published: 2026-09-05 19:16 – Updated: 2026-09-25 15:10 – Source website

Details

The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers. A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.

Severity

5.0 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-18238	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-18238	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libpcap0.8",
            "binary_version": "1.5.3-2ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libpcap",
        "purl": "pkg:deb/ubuntu/libpcap@1.5.3-2ubuntu0.1+esm1?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.0-2",
        "1.5.1-1",
        "1.5.2-1",
        "1.5.3-1",
        "1.5.3-2",
        "1.5.3-2ubuntu0.1",
        "1.5.3-2ubuntu0.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libpcap0.8",
            "binary_version": "1.7.4-2ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libpcap",
        "purl": "pkg:deb/ubuntu/libpcap@1.7.4-2ubuntu0.1+esm1?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.7.4-1",
        "1.7.4-2",
        "1.7.4-2ubuntu0.1",
        "1.7.4-2ubuntu0.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libpcap0.8",
            "binary_version": "1.8.1-6ubuntu1.18.04.2+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libpcap",
        "purl": "pkg:deb/ubuntu/libpcap@1.8.1-6ubuntu1.18.04.2+esm1?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.8.1-5ubuntu1",
        "1.8.1-6ubuntu1",
        "1.8.1-6ubuntu1.18.04.1",
        "1.8.1-6ubuntu1.18.04.2",
        "1.8.1-6ubuntu1.18.04.2+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libpcap0.8",
            "binary_version": "1.9.1-3ubuntu1.20.04.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libpcap",
        "purl": "pkg:deb/ubuntu/libpcap@1.9.1-3ubuntu1.20.04.1+esm1?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.1-2",
        "1.9.1-3",
        "1.9.1-3ubuntu1.20.04.1",
        "1.9.1-3ubuntu1.20.04.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libpcap0.8",
            "binary_version": "1.10.1-4ubuntu1.22.04.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libpcap",
        "purl": "pkg:deb/ubuntu/libpcap@1.10.1-4ubuntu1.22.04.2?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.10.0-2build1",
        "1.10.1-4",
        "1.10.1-4build1",
        "1.10.1-4ubuntu1.22.04.1",
        "1.10.1-4ubuntu1.22.04.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libpcap0.8t64",
            "binary_version": "1.10.4-4.1ubuntu3.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libpcap",
        "purl": "pkg:deb/ubuntu/libpcap@1.10.4-4.1ubuntu3.1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.10.4-4",
        "1.10.4-4ubuntu3",
        "1.10.4-4.1ubuntu2",
        "1.10.4-4.1ubuntu3",
        "1.10.4-4.1ubuntu3.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libpcap0.8t64",
            "binary_version": "1.10.6-1ubuntu1.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libpcap",
        "purl": "pkg:deb/ubuntu/libpcap@1.10.6-1ubuntu1.1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.10.5-2ubuntu2",
        "1.10.5-2ubuntu3",
        "1.10.6-1ubuntu1",
        "1.10.6-1ubuntu1.1"
      ]
    }
  ],
  "aliases": [],
  "details": "The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers.  A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.",
  "id": "UBUNTU-CVE-2026-18238",
  "modified": "2026-09-25T15:10:06Z",
  "published": "2026-09-05T19:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-18238"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-18238"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-18238"
  ]
}

CVE-2026-18238 (GCVE-0-2026-18238)

Vulnerability from cvelistv5 – Published: 2026-09-05 18:51 – Updated: 2026-09-08 15:17

Title

OOBR in rpcap client in libpcap before 1.10.7

Summary

Severity

5 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-08 15:17 UTC

CWE

CWE-1288 - Improper Validation of Consistency within Input
CWE-126 - Buffer Over-read

Assigner

Tcpdump mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/the-tcpdump-group/libpcap/comm…	patch

Impacted products

1 product

Vendor	Product	Version
The Tcpdump Group	libpcap	Affected: 1.8.x Affected: 1.9.x Affected: 1.10.x , < 1.10.7 (semver)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-18238",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-08T15:17:08.655802Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-08T15:17:19.641Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "modules": [
            "remote packet capture client"
          ],
          "product": "libpcap",
          "programFiles": [
            "pcap-rpcap.c"
          ],
          "programRoutines": [
            {
              "name": "pcap_read_nocb_remote()"
            }
          ],
          "repo": "https://github.com/the-tcpdump-group/libpcap/",
          "vendor": "The Tcpdump Group",
          "versions": [
            {
              "status": "affected",
              "version": "1.8.x"
            },
            {
              "status": "affected",
              "version": "1.9.x"
            },
            {
              "lessThan": "1.10.7",
              "status": "affected",
              "version": "1.10.x",
              "versionType": "semver"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "The problem is specific to the remote packet capture code, which is not enabled in the default build configuration."
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers.  A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet."
        }
      ],
      "exploits": [
        {
          "lang": "en",
          "value": "A functional exploit exists."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1288",
              "description": "CWE-1288: Improper Validation of Consistency within Input",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-126",
              "description": "CWE-126 Buffer Over-read",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-05T18:51:57.956Z",
        "orgId": "cfdbb673-b408-4d03-89c1-c3d73ed80896",
        "shortName": "Tcpdump"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/the-tcpdump-group/libpcap/commit/b9590d482986d64673712460aae1d48d11fa0473"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to libpcap 1.10.7."
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "OOBR in rpcap client in libpcap before 1.10.7",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "cfdbb673-b408-4d03-89c1-c3d73ed80896",
    "assignerShortName": "Tcpdump",
    "cveId": "CVE-2026-18238",
    "datePublished": "2026-09-05T18:51:57.956Z",
    "dateReserved": "2026-07-29T13:32:44.322Z",
    "dateUpdated": "2026-09-08T15:17:19.641Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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.

Action not permitted

UBUNTU-CVE-2026-18238 (CVE-2026-18238)

CVE-2026-18238 (GCVE-0-2026-18238)

Tags

Sightings

Nomenclature

Related by attack behaviour