{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "4.1.135"
              },
              {
                "introduced": "4.2.0"
              },
              {
                "fixed": "4.2.15"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f05f765d81460799c53123a207f665bf3b465171"
            },
            {
              "introduced": "09e64d259c99be8b5b2a471a78f11e65eb82598a"
            },
            {
              "fixed": "a41f7b289ce1d697c50846f3ade3983e22b2ed40"
            }
          ],
          "repo": "https://github.com/netty/netty",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-5xrh-qmmq-w6ch"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46340.json"
  },
  "details": "Netty is a network application framework for development of protocol servers and clients. In versions of netty-transport-sctp prior to 4.1.135.Final and 4.2.15.Final, for each non-complete SctpMessage fragment the handler does `fragments.put(streamId, Unpooled.wrappedBuffer(frag, byteBuf))`, wrapping the previous accumulator and the new slice into a *new* CompositeByteBuf every time. After N fragments the accumulator is an N-deep chain of composites, each holding references and component arrays; readableBytes()/getBytes() on the final buffer recurse N levels. There is no limit on N, on total bytes, or on the number of streamIdentifiers an attacker can open (each gets its own map entry). A peer that never sets the `complete` flag can grow this structure indefinitely from tiny 1-byte DATA chunks. Versions 4.1.135.Final and 4.2.15.Final patch the issue.",
  "id": "CVE-2026-46340",
  "modified": "2026-07-23T03:56:11.198920578Z",
  "published": "2026-06-12T14:19:48.855Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46340.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:37390"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:41951"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/security/cve/CVE-2026-46340"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46340.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-5xrh-qmmq-w6ch"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46340"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2488388"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Netty: SCTP reassembly nests buffers without bound"
}