CVE-2026-16158
Description
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.
How to fix
- fastify fastify\/reply-from12.6.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| fastify fastify\/reply-from | 8.3.1 ≤ v < 12.6.4 | 12.6.4 |
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