CVE-2026-78663 affecting package ignition-flatcar 2.22.0-6

{
  "id": "d817acbf52534ce6550ed85f0b98a6ab215ffcea84a30ffd90e6c4b25eb470be",
  "url": "https://osv.dev/vulnerability/AZL-107508",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-78663 affecting package ignition-flatcar 2.22.0-6",
    "summary": "The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.",
    "evidence": "osv:AZL-107508",
    "products": [
      {
        "name": {
          "value": "ignition-flatcar",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "AZL-107508",
      "aliases": [
        "AZL-107508"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "2.22.0-6"
                }
              ]
            }
          ],
          "package": {
            "name": "ignition-flatcar",
            "purl": "pkg:rpm/azure-linux/ignition-flatcar",
            "ecosystem": "Azure Linux:3"
          },
          "database_specific": {
            "source": "https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-107508.json"
          }
        }
      ],
      "modified": "2026-10-15T05:37:09Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-78663"
      ],
      "references": [
        "https://nvd.nist.gov/vuln/detail/CVE-2026-78663"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-78663",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 321485,
  "published_at": "2026-10-08T23:17:03+00:00"
}