CVE-2026-16158 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-16158CRITICAL

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

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  C  H  H  N   10.0   .0023   14.2     —

AFFECTED
  Product              Versions  Fixed
  @fastify/reply-from  8.3.1 –   12.6.4

TIMELINE
  Jul 17  Reserved by openjs
  Jul 18  Published (CNA: openjs)
  Aug 5   RESCORED — CVE-2026-16158 (@fastify/reply-from). CVSS 8.7 → 10 (NVD).

CWE-441 · CNA: openjs · CVSS v3.1 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 17, 2026	Reserved	Reserved by openjs
July 18, 2026	Published	Published (CNA: openjs)
August 5, 2026	RESCORED	RESCORED — CVE-2026-16158 (@fastify/reply-from). CVSS 8.7 → 10 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
@fastify/reply-from	@fastify/reply-from	—	8.3.1	12.6.4

Weaknesses

CWE-441

References (2)

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

Authoritative record: CVE-2026-16158 at cve.org

Vendors: @fastify/reply-from

Weaknesses: CWE-441

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-16158 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.