Critical 9.3Published Feb 25, 2026

CVE-2026-27804Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter

Updated under an hour ago (Oct 26, 2026, 9:00 PM ET)

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It affects parse-community parse-server and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for parse-community parse-server

Exploited in the last 30 days

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.3 and 9.1.1-alpha.4, an unauthenticated attacker can forge a Google authentication token with `alg: "none"` to log in as any user linked to a Google account, without knowing their credentials. All deployments with Google authentication enabled are affected. The fix in versions 8.6.3 and 9.1.1-alpha.4 hardcodes the expected `RS256` algorithm instead of trusting the JWT header, and replaces the Google adapter's custom key fetcher with `jwks-rsa` which rejects unknown key IDs. As a workaround, dsable Google authentication until upgrading is possible.

CVSS: 9.3 CRITICAL (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Weakness (CWE): CWE-327, CWE-345
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Feb 26, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

parse-community parse-server parse_community:parse_server (from the name)	from 9.0.0, < 9.3.1-alpha.4; before 8.6.3	CNA record
parseplatform parse-server parseplatform:parse-server	before 8.6.3; from 9.0.0 before 9.3.1; 9.3.1; 9.3.1; 9.3.1	NVD

References

References

https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2	x-refsource-confirm, patch, vendor-advisory
https://github.com/parse-community/parse-server/commit/9b94083accb7f3e72c6b8126c195c7a03dd2dfd7	x-refsource-misc, patch
https://github.com/parse-community/parse-server/commit/9d5942d50e55c822924c27b05aa98f1393e7a330	x-refsource-misc, patch
https://github.com/parse-community/parse-server/releases/tag/8.6.3	x-refsource-misc, release-notes
https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.