Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP

{
  "id": "a01e7c879f31a1fc46f63a76ff0022fc630648d1cc632e5f14bfbb9128677584",
  "url": "https://osv.dev/vulnerability/CVE-2026-7426",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP",
    "summary": "Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted. To mitigate this issue, users should upgrade to the fixed version when available.",
    "evidence": "osv:CVE-2026-7426",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-7426",
      "aliases": [
        "CVE-2026-7426",
        "GHSA-97qg-4359-xm3x"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/freertos/freertos-plus-tcp",
              "type": "GIT",
              "events": [
                {
                  "introduced": "3e26a338bd1547bbaa6f4965def1a4b152620d3e"
                },
                {
                  "fixed": "5986530664073a609e634bde63dd9bff37e725f0"
                },
                {
                  "introduced": "dd4d689acc04015e5a2a3ef2cebb6725f55c60be"
                },
                {
                  "fixed": "c12361095aca68aeed858f45d14395fbffa92c0d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.0.0"
                      },
                      {
                        "fixed": "4.2.6"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.3.0"
                      },
                      {
                        "fixed": "4.4.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "5986530664073a609e634bde63dd9bff37e725f0"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "V4.2.6"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c12361095aca68aeed858f45d14395fbffa92c0d"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "V4.4.1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "V4.2.5",
            "V4.4.0",
            "V4.2.4",
            "V4.2.3",
            "V4.2.2",
            "V4.2.1",
            "V4.2.0",
            "V4.0.0-appsec"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-7426.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.889134442Z",
      "provider": "osv",
      "references": [
        "https://aws.amazon.com/security/security-bulletins/2026-023-aws/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7426.json",
        "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-97qg-4359-xm3x",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-7426",
        "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6",
        "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1",
        "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-787"
        ],
        "cna_assigner": "AMZN",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7426.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-7426",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491360,
  "published_at": "2026-04-29T18:53:52.187+00:00"
}