VulnerabilityAwaiting Analysis

CVE-2026-117499

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.

LOW 3.7EPSS —

Does this matter?

Lower severity and no EPSS score yet. Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 3.7 LOWCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N
EPSS: No score yet
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-362, CWE-613
Source: ce714d77-add3-4f53-aff5-83d477b104bb

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.