Uncaught Exception in Fastify - CVE-2026-92081
Published: September 17, 2026
Vulnerability identifier: #VU150746
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-92081
CWE-ID: CWE-248
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an uncaught exception in Fastify's HTTP/2 response trailer handling when serializing a response with a registered trailer. A remote attacker can send an HTTP/2 request to a route that registers a response trailer to cause a denial of service.
Applications are affected only when HTTP/2 is enabled and at least one route registers a trailer; HTTP/1.x responses are not affected.
Affected software
Fastify
How to mitigate CVE-2026-92081
Install security update from vendor's website.
Fastify - update to 5.12.5