GHSA-pfj7-wv7c-22pr — high GitHub Advisory (CVE-2026-33409) in npm/parse-server

Description

Impact

An authentication bypass vulnerability allows an attacker to log in as any user who has linked a third-party authentication provider, without knowing the user's credentials. The attacker only needs to know the user's provider ID to gain full access to their account, including a valid session token.

This affects Parse Server deployments where the server option allowExpiredAuthDataToken is set to true. The default value is false.

Patches

Auth providers are now always validated on login, regardless of the allowExpiredAuthDataToken setting. The option allowExpiredAuthDataToken has been deprecated and will be removed in a future major version.

Workarounds

Set allowExpiredAuthDataToken to false (the default) or remove the option from the server configuration.

Basic information

Type: reviewed
Severity: high
Advisory on GitHub: Open advisory ↗
Repository advisory: Open repository advisory ↗
Source code: Browse source ↗
Published (advisory): 2026-03-19 21:32:10 UTC
Updated: 2026-03-30 13:51:12 UTC
GitHub reviewed: 2026-03-19 21:32:10 UTC
NVD published: 2026-03-24

Score	Percentile
0.07%	21.15%

CVSS Scores

Base score	Version	Severity	Vector
9.1	3.1	—	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.
7.0	4.0	—	`CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network. Attack complexity (AC:H) Exploitation depends on constrained or hard-to-reproduce conditions. Attack requirements (AT:P) Additional preconditions must be present for exploitation. Privileges required (PR:H) High privileges are required. User interaction (UI:A) User interaction is required in an active way. Vulnerable system confidentiality impact (VC:H) High confidentiality impact on the vulnerable system. Vulnerable system integrity impact (VI:H) High integrity impact on the vulnerable system. Vulnerable system availability impact (VA:N) No availability impact on the vulnerable system. Subsequent system confidentiality impact (SC:N) No confidentiality impact on subsequent systems. Subsequent system integrity impact (SI:N) No integrity impact on subsequent systems. Subsequent system availability impact (SA:N) No availability impact on subsequent systems.

Identifiers

Type	Value
GHSA	GHSA-pfj7-wv7c-22pr ↗
CVE	CVE-2026-33409 ↗

CWEs

CWE id	Name
CWE-287	Improper Authentication

Credits

offset (reporter)
mtrezza (coordinator)

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem	Package	Vulnerable range	First patched	Vulnerable functions
npm	parse-server	>= 9.0.0, < 9.6.0-alpha.41	9.6.0-alpha.41	—
npm	parse-server	< 8.6.52	8.6.52	—

Parse Server has an auth provider validation bypass on login via partial authData