CVE-2026-107318

HIGHCVSS 7.4/10

Last modified

CVE-2026-107318 is a high-severity vulnerability rated 7.4/10 on the CVSS scale. @fastify/reply-from is a Fastify plugin that forwards requests to an upstream HTTP or HTTPS server. In versions prior to 12.7.0, all of the built-in HTTPS transports override the secure default and set rejectUnauthorized to false, so the proxy does not verify the TLS certificate of the upstream even when the application points it at an https upstream in the default configuration.

Description

@fastify/reply-from is a Fastify plugin that forwards requests to an upstream HTTP or HTTPS server. In versions prior to 12.7.0, all of the built-in HTTPS transports override the secure default and set rejectUnauthorized to false, so the proxy does not verify the TLS certificate of the upstream even when the application points it at an https upstream in the default configuration. An on-path network attacker can therefore impersonate the configured HTTPS upstream, read the credentials and request bodies the proxy forwards, and return forged responses that the application trusts. The issue is fixed in @fastify/reply-from 12.7.0, and users should upgrade to 12.7.0 or later. As a workaround, pass an explicit rejectUnauthorized true on the transport, supply an already configured undici instance, or use the undici global agent.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
@fastify/reply-from@fastify/reply-from< 12.7.0

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-107318?
@fastify/reply-from is a Fastify plugin that forwards requests to an upstream HTTP or HTTPS server. In versions prior to 12.7.0, all of the built-in HTTPS transports override the secure default and set rejectUnauthorized to false, so the proxy does not verify the TLS certificate of the upstream even when the application points it at an https upstream in the default configuration. An on-path network attacker can therefore impersonate the configured HTTPS upstream, read the credentials and request bodies the proxy forwards, and return forged responses that the application trusts. The issue is fixed in @fastify/reply-from 12.7.0, and users should upgrade to 12.7.0 or later. As a workaround, pass an explicit rejectUnauthorized true on the transport, supply an already configured undici instance, or use the undici global agent.
How severe is CVE-2026-107318?
CVE-2026-107318 has a CVSS score of 7.4/10 (HIGH severity).
How do I fix CVE-2026-107318?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST