CVE-2026-16158

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.

CVSS v3 8.7 HIGH

8.7^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.8

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://cna.openjsf.org/security-advisories.html
https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-v574-6498-x57v

Configurations

No configuration.

History

18 Jul 2026, 13:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-18 13:17

Updated : 2026-07-21 18:31

NVD link : CVE-2026-16158

Mitre link : CVE-2026-16158

CVE.ORG link : CVE-2026-16158

JSON object : View

Products Affected

No product.

CWE

CWE-441

Unintended Proxy or Intermediary ('Confused Deputy')

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