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CVE-2026-16158

@fastify/reply-from vulnerable to cross-upstream request routing via URL cache key collision

Published: Jul 18, 2026Updated: Aug 5, 2026 Sources: CVE List NVDCWE-441
8.7HIGH
NVD MITRE
EPSS Score
0.2%
Top 86.1%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:CC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-441

Affected Products

fastify
oss-projectaka fastify-multipart, fastify/middie
fastify\/reply-fromLibrary
OSS Libraries / web-framework
@fastify/reply-from
oss-project
@fastify/reply-fromLibrary
OSS Libraries / web-framework

Exploitability

Official Patch Available
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References

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

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