REDHAT-BUG-2458651: High severity npm/@fastify/reply-from vulnerability
@fastify/reply-from v12.6.1 and earlier and @fastify/http-proxy v11.4.3 and earlier process the client's Connection header after the proxy has added its own headers via rewriteRequestHeaders. This allows attackers to retroactively strip proxy-added headers from upstream requests by listing them in the Connection header value. Any header added by the proxy for routing, access control, or security purposes can be selectively removed by a client. @fastify/http-proxy is also affected as it delegates to @fastify/reply-from.
Upgrade to @fastify/reply-from v12.6.2 or @fastify/http-proxy v11.4.4 or later.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
@fastify/reply-fromto a version that resolves this vulnerability.Fixed in 12.6.2 - Upgrade
Upgrade
@fastify/http-proxyto a version that resolves this vulnerability.Fixed in 11.4.4
Event History
Frequently Asked Questions
What is the severity of REDHAT-BUG-2458651?
The severity of REDHAT-BUG-2458651 is classified as high, with a score of 7.
How do I fix REDHAT-BUG-2458651?
To fix REDHAT-BUG-2458651, you should upgrade to @fastify/reply-from version 12.6.2 or later and @fastify/http-proxy version 11.4.4 or later.
What are the potential impacts of REDHAT-BUG-2458651?
The potential impacts of REDHAT-BUG-2458651 include the ability for attackers to remove proxy-added headers from upstream requests.
Which software is affected by REDHAT-BUG-2458651?
The software affected by REDHAT-BUG-2458651 includes npm/@fastify/reply-from versions 12.6.1 and earlier, and npm/@fastify/http-proxy versions 11.4.3 and earlier.
When was REDHAT-BUG-2458651 published?
REDHAT-BUG-2458651 was published on April 15, 2026.