osrg GoBGP bgp.go DecodeFromBytes off-by-one

{
  "id": "7f14a5ff209d7da242bb469b452ca0f3fdaa6a998cb88b6d45337050f38185ce",
  "url": "https://osv.dev/vulnerability/CVE-2026-5123",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "osrg GoBGP bgp.go DecodeFromBytes off-by-one",
    "summary": "A weakness has been identified in osrg GoBGP up to 4.3.0. This impacts the function DecodeFromBytes of the file pkg/packet/bgp/bgp.go. Executing a manipulation of the argument data[1] can lead to off-by-one. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is said to be difficult. This patch is called 67c059413470df64bc20801c46f64058e88f800f. A patch should be applied to remediate this issue.",
    "evidence": "osv:CVE-2026-5123",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-5123",
      "aliases": [
        "CVE-2026-5123"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/osrg/gobgp",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c9c1c120495527d231cfebce28b29a8924717d6c"
                },
                {
                  "fixed": "67c059413470df64bc20801c46f64058e88f800f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4.0"
                      },
                      {
                        "last_affected": "4.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "introduced": "4.1"
                      },
                      {
                        "last_affected": "4.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "introduced": "4.2"
                      },
                      {
                        "last_affected": "4.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "introduced": "4.3.0"
                      },
                      {
                        "last_affected": "4.3.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "fixed": "67c059413470df64bc20801c46f64058e88f800f"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.0",
            "4.1",
            "4.2",
            "4.3.0",
            "v4.3.0",
            "v4.2.0",
            "v4.1.0",
            "v4.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-5123.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:31.566236635Z",
      "provider": "osv",
      "references": [
        "https://github.com/osrg/gobgp/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5123.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-5123",
        "https://vuldb.com/submit/780179",
        "https://vuldb.com/vuln/354155",
        "https://vuldb.com/vuln/354155/cti",
        "https://github.com/osrg/gobgp/commit/67c059413470df64bc20801c46f64058e88f800f",
        "https://github.com/osrg/gobgp/pull/3342"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-189",
          "CWE-193"
        ],
        "cna_assigner": "VulDB",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5123.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-5123",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 498587,
  "published_at": "2026-03-30T15:15:14.229+00:00"
}