{"id":"CVE-2026-16158","summary":"@fastify/reply-from vulnerable to cross-upstream request routing via URL cache key collision","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.","aliases":["GHSA-v574-6498-x57v"],"modified":"2026-07-23T03:56:07.977225492Z","published":"2026-07-18T12:28:17.262Z","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"},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/fastify/fastify-reply-from","events":[{"introduced":"85eee1901102e804faf9557d839b565020309ead"},{"fixed":"08e537c8b7b8100b8ffb677611301f7612fb15fe"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"8.3.1"},{"fixed":"12.6.4"}]}}],"versions":["v12.6.3","v12.6.2","v12.6.1","v12.5.0","v12.4.0","v12.3.1","v12.3.0","v12.2.0","v12.1.0","v12.0.2","v12.0.1","v12.0.0","v11.0.2","v11.0.1","v11.0.0","v9.8.0","v9.7.0","v9.6.0","v9.5.0","v9.4.0","v4.18.0","v9.3.0","v9.2.0","v9.1.0","v9.0.2","v10.0.0","v9.0.1","v9.0.0","v8.4.3","v8.4.2","v8.4.1","v8.4.0","v8.3.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-16158.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N"}]}