Widespread Parse Server deployments with Google auth; unauthenticated token forgery enables account compromise.
CVE-2026-27804
Unauthenticated Google JWT forgery enables login as any Google-linked user.
Is CVE-2026-27804 being exploited?
Not confirmed. CVE-2026-27804 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.18% probability of exploitation in the next 30 days.
How severe is CVE-2026-27804?
CVE-2026-27804 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-27804?
Yes. A fix has been recorded for CVE-2026-27804. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-27804 affect?
CVE-2026-27804 affects Parse Server (Node.js), Deployments with Google Authentication enabled, Versions < 8.6.3 and < 9.1.1-alpha.4. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-27804?
Upgrade to 8.6.3 or 9.1.1-alpha.4; temporarily disable Google auth.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Impersonation of any Google-linked user via forged JWT (alg: none) enables unauthorized access and data exposure.
Patch when possible
- affected>= 9.0.0 and < 9.3.1-alpha.4
- affected< 8.6.3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.