@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.
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Tue, 27 Oct 2026 11:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | @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. | |
| Title | @fastify/session vulnerable to session revocation bypass via a logout race condition | |
| Weaknesses | CWE-362 CWE-613 |
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cvssV3_1
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Status: PUBLISHED
Assigner: openjs
Published:
Updated: 2026-10-27T11:19:22.090Z
Reserved: 2026-10-27T08:37:38.311Z
Link: CVE-2026-117499
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Status : Awaiting Analysis
Published: 2026-10-27T12:17:07.370
Modified: 2026-10-27T15:03:41.023
Link: CVE-2026-117499
No data.
OpenCVE Enrichment
Updated: 2026-10-27T13:30:04Z