{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "8.3.1"
              },
              {
                "fixed": "12.6.4"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "85eee1901102e804faf9557d839b565020309ead"
            },
            {
              "fixed": "08e537c8b7b8100b8ffb677611301f7612fb15fe"
            }
          ],
          "repo": "https://github.com/fastify/fastify-reply-from",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-v574-6498-x57v"
  ],
  "database_specific": {
    "cna_assigner": "openjs",
    "cwe_ids": [
      "CWE-441"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16158.json"
  },
  "details": "Impact: @fastify/reply-from versions from 8.3.1 up to but not including 12.6.4 build the internal URL cache key by concatenating the destination and source path without a delimiter. Different destination and source pairs can therefore produce the same key while resolving to different upstream URLs. When getUpstream selects an upstream from request data, a URL cached for one upstream can be reused for a request intended for another upstream, causing cross-upstream data access and modification. The default configuration is affected. Setting disableCache to true prevents the behavior. Patches: upgrade to @fastify/reply-from 12.6.4. Workarounds: pass disableCache: true when registering the plugin.",
  "id": "CVE-2026-16158",
  "modified": "2026-07-23T03:56:07.977225492Z",
  "published": "2026-07-18T12:28:17.262Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16158.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-v574-6498-x57v"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-16158"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "@fastify/reply-from vulnerable to cross-upstream request routing via URL cache key collision"
}