Security advisory

{
  "id": "a5f2f03251ead52d5239260920ada34f96425ae9bd876e071654b492111e42ef",
  "url": "https://osv.dev/vulnerability/CVE-2026-50052",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-50052",
    "summary": "In Vinyl Cache before 9.0.1 and Varnish Cache before 9.0.3, a deficiency in HTTP/2 request parsing can be exploited to launch a backend request desync attack (request smuggling), which in turn can be used for cache poisoning, authentication bypass, or possibly even information disclosure and manipulation. The attack vector only exists if HTTP/2 support is enabled by setting the feature parameter to contain +http2. HTTP/2 support is disabled by default.",
    "evidence": "osv:CVE-2026-50052",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-50052",
      "aliases": [
        "CVE-2026-50052"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/S:N/AU:N/R:A/V:D/RE:L/U:Green"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/varnish/varnish",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ce1b315b0c35477c666e4c8d8e1c9174df87eb61"
                },
                {
                  "last_affected": "ce1b315b0c35477c666e4c8d8e1c9174df87eb61"
                },
                {
                  "last_affected": "dc27a2dce662015cf79bbda5ff193b6bb74ba2d1"
                },
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "4883a9619d9fcdc4efcd7e4cd7e355ee38521a84"
                },
                {
                  "last_affected": "04286a233e14a5674f86118da1c52ab63152006c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "9.0.0"
                      },
                      {
                        "last_affected": "9.0.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "introduced": "9.0.0"
                      },
                      {
                        "last_affected": "9.0.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "7.6.0"
                      },
                      {
                        "last_affected": "8.0.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "6.0.14"
                      },
                      {
                        "last_affected": "6.0.17"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "9.0.0",
            "varnish-8.0.1",
            "varnish-6.0.17",
            "varnish-9.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50052.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.723773331Z",
      "provider": "osv",
      "references": [
        "https://code.vinyl-cache.org/vinyl-cache/vinyl-cache",
        "https://vinyl-cache.org/security/VSV00019.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50052.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50052",
        "https://github.com/varnish/varnish"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-444"
        ],
        "cna_assigner": "mitre",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50052.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-50052",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517971,
  "published_at": "2026-06-03T03:56:01.974+00:00"
}