CVE-2026-6554 (GCVE-0-2026-6554)

Vulnerability from cvelistv5 – Published: 2026-09-05 18:51 – Updated: 2026-09-08 15:15
VLAI
Title
infinte loop in libpcap before 1.10.7
Summary
libpcap BPF interpreter treats the offset in the 'ja L' BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations. In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely.
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/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 2026-09-08 15:14 UTC
CWE
  • CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
Assigner
References
Impacted products
Vendor Product Version CPE status
The Tcpdump Group libpcap Affected: 0 , < 1.10.7 (semver)
guessed Create a notification for this product.
Credits
Kaixuan LI
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-6554",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-08T15:14:56.820512Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-08T15:15:06.137Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "modules": [
            "BPF interpreter"
          ],
          "product": "libpcap",
          "programFiles": [
            "bpf_filter.c"
          ],
          "programRoutines": [
            {
              "name": "pcapint_filter_with_aux_data()"
            }
          ],
          "repo": "https://github.com/the-tcpdump-group/libpcap/",
          "vendor": "The Tcpdump Group",
          "versions": [
            {
              "lessThan": "1.10.7",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "The problem is specific to applications that use pcap_offline_filter() or bpf_filter() with an externally-supplied compiled filter program without validating the program first."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Kaixuan LI"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "libpcap BPF interpreter treats the offset in the \u0027ja L\u0027 BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations.  In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely."
        }
      ],
      "exploits": [
        {
          "lang": "en",
          "value": "A functional exploit exists."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 5.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-835",
              "description": "CWE-835 Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-05T18:51:02.338Z",
        "orgId": "cfdbb673-b408-4d03-89c1-c3d73ed80896",
        "shortName": "Tcpdump"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/the-tcpdump-group/libpcap/commit/ff3c83475ac303c6b681c52ad0b6e14795a8e0ce"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to libpcap 1.10.7."
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "infinte loop in libpcap before 1.10.7",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "cfdbb673-b408-4d03-89c1-c3d73ed80896",
    "assignerShortName": "Tcpdump",
    "cveId": "CVE-2026-6554",
    "datePublished": "2026-09-05T18:51:02.338Z",
    "dateReserved": "2026-04-17T22:00:24.313Z",
    "dateUpdated": "2026-09-08T15:15:06.137Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-6554",
      "date": "2026-09-27",
      "epss": "0.00105",
      "percentile": "0.00987"
    },
    "microsoft_vex": {
      "current_release_date": "2026-09-15T01:53:09.000Z",
      "cve": "CVE-2026-6554",
      "id": "msrc_CVE-2026-6554",
      "initial_release_date": "2026-09-07T01:02:10.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "2",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "infinte loop in libpcap before 1.10.7",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-6554.json",
      "version": "6"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "modules": [
                  "BPF interpreter"
                ],
                "product": "libpcap",
                "programFiles": [
                  "bpf_filter.c"
                ],
                "programRoutines": [
                  {
                    "name": "pcapint_filter_with_aux_data()"
                  }
                ],
                "repo": "https://github.com/the-tcpdump-group/libpcap/",
                "vendor": "The Tcpdump Group",
                "versions": [
                  {
                    "lessThan": "1.10.7",
                    "status": "affected",
                    "version": "0",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "security@tcpdump.org"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "libpcap BPF interpreter treats the offset in the \u0027ja L\u0027 BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations.  In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely."
          }
        ],
        "id": "CVE-2026-6554",
        "lastModified": "2026-09-08T19:20:25.117",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 5.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 3.6,
              "source": "security@tcpdump.org",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-6554",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-08T15:14:56.820512Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-09-05T19:16:56.067",
        "references": [
          {
            "source": "security@tcpdump.org",
            "url": "https://github.com/the-tcpdump-group/libpcap/commit/ff3c83475ac303c6b681c52ad0b6e14795a8e0ce"
          }
        ],
        "sourceIdentifier": "security@tcpdump.org",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-835"
              }
            ],
            "source": "security@tcpdump.org",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-09T16:11:01+00:00",
      "cve": "CVE-2026-6554",
      "id": "CVE-2026-6554",
      "initial_release_date": "2026-09-05T18:51:02.338000+00:00",
      "product_status:known_affected": "13",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "libpcap: libpcap: Denial of Service via infinite loop in BPF interpreter",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6554.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "low",
      "current_release_date": "2026-09-23T23:50:39Z",
      "cve": "CVE-2026-6554",
      "id": "CVE-2026-6554",
      "initial_release_date": "2026-09-09T00:27:37Z",
      "product_status:first_fixed": "9",
      "product_status:known_affected": "445",
      "product_status:recommended": "47",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-6554",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-6554.json",
      "version": "9"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-6554",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-09-08T15:14:56.820512Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-09-08T15:15:00.849Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "modules": [
                "BPF interpreter"
              ],
              "product": "libpcap",
              "programFiles": [
                "bpf_filter.c"
              ],
              "programRoutines": [
                {
                  "name": "pcapint_filter_with_aux_data()"
                }
              ],
              "repo": "https://github.com/the-tcpdump-group/libpcap/",
              "vendor": "The Tcpdump Group",
              "versions": [
                {
                  "lessThan": "1.10.7",
                  "status": "affected",
                  "version": "0",
                  "versionType": "semver"
                }
              ]
            }
          ],
          "configurations": [
            {
              "lang": "en",
              "value": "The problem is specific to applications that use pcap_offline_filter() or bpf_filter() with an externally-supplied compiled filter program without validating the program first."
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "reporter",
              "value": "Kaixuan LI"
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "libpcap BPF interpreter treats the offset in the \u0027ja L\u0027 BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations.  In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely."
            }
          ],
          "exploits": [
            {
              "lang": "en",
              "value": "A functional exploit exists."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 5.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "format": "CVSS",
              "scenarios": [
                {
                  "lang": "en",
                  "value": "GENERAL"
                }
              ]
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-835",
                  "description": "CWE-835 Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-09-05T18:51:02.338Z",
            "orgId": "cfdbb673-b408-4d03-89c1-c3d73ed80896",
            "shortName": "Tcpdump"
          },
          "references": [
            {
              "tags": [
                "patch"
              ],
              "url": "https://github.com/the-tcpdump-group/libpcap/commit/ff3c83475ac303c6b681c52ad0b6e14795a8e0ce"
            }
          ],
          "solutions": [
            {
              "lang": "en",
              "value": "Upgrade to libpcap 1.10.7."
            }
          ],
          "source": {
            "discovery": "EXTERNAL"
          },
          "title": "infinte loop in libpcap before 1.10.7",
          "x_generator": {
            "engine": "cvelib 1.8.0"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "cfdbb673-b408-4d03-89c1-c3d73ed80896",
        "assignerShortName": "Tcpdump",
        "cveId": "CVE-2026-6554",
        "datePublished": "2026-09-05T18:51:02.338Z",
        "dateReserved": "2026-04-17T22:00:24.313Z",
        "dateUpdated": "2026-09-08T15:15:06.137Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.



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.