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CVE-2026-55617GHSA-94JP-7776-QJ6Q

Hydro: Insufficient session expiration when recreating sessions

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.0.2
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

Hydro is a next-generation high-performance online judge platform. From 4.10.4 until 5.0.2, the session recreation logic in packages/hydrooj/src/service/layers/base.ts creates a replacement session token without deleting the previous token from the server-side session token store, so an old sid cookie can remain valid after logout or another renewal flow. An attacker who possesses a victim's previously valid stale cookie can replay it over HTTP or HTTPS without knowing the victim's username or password and without victim interaction at exploitation time. Successful replay can take over the victim's account, disclose private data, and permit unauthorized modification or deletion of data available to that account. This issue is fixed in version 5.0.2.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • hydro-dev Hydro

    From 4.10.4 · fixed in 5.0.2

  • hydroojnpm

    From 4.10.4 · fixed in 5.0.2

References 4

GitHub · hydro-dev/Hydro