Vulnerability-Lookup

CVE-2026-48691 (GCVE-0-2026-48691)

Vulnerability from cvelistv5 – Published: 2026-05-26 00:00 – Updated: 2026-05-27 20:37

Summary

FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as 'sizeof(bgp_as_path_segment_element_t) + this->as_path_asns.size() * sizeof(uint32_t)' and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 > 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.

Severity

7.3 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-27 20:37 UTC

CWE

n/a
CWE-190 - Integer Overflow or Wraparound
CWE-122 - Heap-based Buffer Overflow

Assigner

mitre

References

3 references

URL	Tags
https://github.com/pavel-odintsov/fastnetmon
https://github.com/pavel-odintsov/fastnetmon/blob…
https://lorikeetsecurity.com/blog/fastnetmon-cve-…

Show details on NVD website

JSON

To clipboard

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        "metrics": [
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              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
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FKIE_CVE-2026-48691

Vulnerability from fkie_nvd - Published: 2026-05-26 17:16 - Updated: 2026-06-17 10:55

Severity

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.3 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Summary

References

URL	Tags
cve@mitre.org	https://github.com/pavel-odintsov/fastnetmon	Product
cve@mitre.org	https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp	Product
cve@mitre.org	https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48691-bgp-as-path-overflow	Third Party Advisory

Impacted products

	Vendor	Product	Version
	pavel-odintsov	fastnetmon	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "source": "cve@mitre.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
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          "cpeMatch": [
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              "criteria": "cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*",
              "matchCriteriaId": "E712A01F-3AD7-4CC2-9A8B-F8C63756EBBF",
              "versionEndIncluding": "1.2.9",
              "vulnerable": true
            }
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          "negate": false,
          "operator": "OR"
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as \u0027sizeof(bgp_as_path_segment_element_t) + this-\u003eas_path_asns.size() * sizeof(uint32_t)\u0027 and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 \u003e 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs."
    }
  ],
  "id": "CVE-2026-48691",
  "lastModified": "2026-06-17T10:55:11.290",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
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        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      },
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        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
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          "confidentialityImpact": "LOW",
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          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
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        "impactScore": 3.4,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
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    "ssvcV203": [
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        "ssvcData": {
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          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
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          "role": "CISA Coordinator",
          "timestamp": "2026-05-27T20:37:39.723368Z",
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      "tags": [
        "Product"
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      "source": "cve@mitre.org",
      "tags": [
        "Product"
      ],
      "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp"
    },
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  "vulnStatus": "Modified",
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        }
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      "type": "Primary"
    },
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          "value": "CWE-190"
        }
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  ]
}

GHSA-PJMC-GJWH-QR2W

Vulnerability from github – Published: 2026-05-26 18:31 – Updated: 2026-05-27 15:33

Details

Severity

9.8 (Critical)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-48691"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122",
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-26T17:16:53Z",
    "severity": "CRITICAL"
  },
  "details": "FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as \u0027sizeof(bgp_as_path_segment_element_t) + this-\u003eas_path_asns.size() * sizeof(uint32_t)\u0027 and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 \u003e 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.",
  "id": "GHSA-pjmc-gjwh-qr2w",
  "modified": "2026-05-27T15:33:00Z",
  "published": "2026-05-26T18:31:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48691"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pavel-odintsov/fastnetmon"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp"
    },
    {
      "type": "WEB",
      "url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48691-bgp-as-path-overflow"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

ubuntu-cve-2026-48691

Vulnerability from osv_ubuntu

Published

2026-05-26 17:16

Modified

2026-06-16 03:06

Summary

Details

Severity

9.8 (Critical)


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

7.3 (High)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-48691	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-48691	REPORT
	https://lorikeetsecurity.com/blog/fastnetmon-cve-…	REPORT
	https://github.com/pavel-odintsov/fastnetmon/comm…	REPORT
	https://github.com/pavel-odintsov/fastnetmon/pull/1054	REPORT
	https://github.com/pavel-odintsov/fastnetmon	REPORT
	https://github.com/pavel-odintsov/fastnetmon/blob…	REPORT
	https://ubuntu.com/security/notices/USN-8429-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "fastnetmon",
            "binary_version": "1.2.6-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "fastnetmon",
        "purl": "pkg:deb/ubuntu/fastnetmon@1.2.6-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.6-1ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.5-1",
        "1.2.6-1",
        "1.2.6-1build1",
        "1.2.6-1build2",
        "1.2.6-1build3",
        "1.2.6-1build4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "fastnetmon",
            "binary_version": "1.2.8+git20250911-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "fastnetmon",
        "purl": "pkg:deb/ubuntu/fastnetmon@1.2.8+git20250911-1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.8-1build1",
        "1.2.8-1build2",
        "1.2.8+git20250911-1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "fastnetmon",
            "binary_version": "1.2.8+git20250911-2ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "fastnetmon",
        "purl": "pkg:deb/ubuntu/fastnetmon@1.2.8+git20250911-2ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.8+git20250911-2ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.8+git20250911-1",
        "1.2.8+git20250911-1build1",
        "1.2.8+git20250911-1build2",
        "1.2.8+git20250911-2"
      ]
    }
  ],
  "aliases": [],
  "details": "FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as \u0027sizeof(bgp_as_path_segment_element_t) + this-\u003eas_path_asns.size() * sizeof(uint32_t)\u0027 and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 \u003e 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.",
  "id": "UBUNTU-CVE-2026-48691",
  "modified": "2026-06-16T03:06:13Z",
  "published": "2026-05-26T17:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-48691"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-48691"
    },
    {
      "type": "REPORT",
      "url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48691-bgp-as-path-overflow"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pavel-odintsov/fastnetmon/commit/94c66d5b100c42fb8bd10a22ca595e46895d60d0"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pavel-odintsov/fastnetmon/pull/1054"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pavel-odintsov/fastnetmon"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.hpp"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8429-1"
    }
  ],
  "related": [
    "USN-8429-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-48691"
  ]
}

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.

Action not permitted

CVE-2026-48691 (GCVE-0-2026-48691)

FKIE_CVE-2026-48691

GHSA-PJMC-GJWH-QR2W

ubuntu-cve-2026-48691

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature