CVE-2026-117499
CVE-2026-117499 updated by NVD
Summary
@fastify/session is a session plugin for Fastify. In all releases before 11.1.6, with the default rolling session behavior, a request that restored a session before a logout could save its own copy after another request had completed the session destroy call, recreating the destroyed session identifier with its authenticated data. An attacker who already holds a victim's valid signed session cookie and keeps a request in flight across the logout can replay that cookie to restore the session after it was meant to be revoked, without any cookie theft or signature forgery. The issue is fixed in @fastify/session 11.1.6, which adds a per session generation marker and a conditional store write so a session restored before a logout or regeneration cannot recreate or overwrite the current entry, and users should upgrade to 11.1.6 or later. There is no workaround, and custom session stores must implement the new conditional write.
References
Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.
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