{"id":"CVE-2026-16158","title":"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","summary":"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 pr…","severity":"high","cvss":8.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","cwe":["CWE-441"],"published":"2026-07-18","updated":"2026-07-18","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-16158","references":[{"url":"https://cna.openjsf.org/security-advisories.html","label":"ce714d77-add3-4f53-aff5-83d477b104bb"},{"url":"https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-v574-6498-x57v","label":"ce714d77-add3-4f53-aff5-83d477b104bb"}],"tags":["nvd"],"ingestedAt":"2026-07-19T03:27:58.168Z","epss":0.00231,"epssPercentile":0.14205,"slug":"CVE-2026-16158","body":"## Overview\n\nImpact: @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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":47.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}