Parse Server has a login timing side-channel reveals user existence
Priority LOW 28CWE-208Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-208.
Summary
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.8.0-alpha.6 and 8.6.74, he login endpoint response time differs measurably depending on whether the submitted username or email exists in the database. When a user is not found, the server responds immediately. When a user exists but the password is wrong, a bcrypt comparison runs first, adding significant latency. This timing difference allows an unauthenticated attacker to enumerate valid usernames. This vulnerability is fixed in 9.8.0-alpha.6 and 8.6.74.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00239 15th percentileScored 2026-11-07
Fix Fixed parse-server (parse-community): 9.8.0-alpha.6, 8.6.74parse-server (npm): 9.8.0-alpha.6, 8.6.74
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| parse-community | parse-server | 9.0.0 to before 9.8.0-alpha.6; before 8.6.74 | 9.8.0-alpha.6, 8.6.74 | Patch available | CNA |
| — | parse-server (npm) | 9.0.0 to before 9.8.0-alpha.6 | 9.8.0-alpha.6 | Patch available | GHSA-mmpq-5hcv-hf2v |
| — | parse-server (npm) | before 8.6.74 | 8.6.74 | Patch available | GHSA-mmpq-5hcv-hf2v |
- parse-server Vendorparse-community Affected 9.0.0 to before 9.8.0-alpha.6; before 8.6.74 Fixed in 9.8.0-alpha.6, 8.6.74 Patch available CNA
- parse-server (npm) Vendor— Affected 9.0.0 to before 9.8.0-alpha.6 Fixed in 9.8.0-alpha.6 Patch available GHSA-mmpq-5hcv-hf2v
- parse-server (npm) Vendor— Affected before 8.6.74 Fixed in 8.6.74 Patch available GHSA-mmpq-5hcv-hf2v
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* | before 8.6.74; 9.0.0 to before 9.8.0 | Vulnerable | parse-community |
| cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha1:*:*:*:node.js:*:* | 9.8.0 alpha1 | Vulnerable | parse-community |
| cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha2:*:*:*:node.js:*:* | 9.8.0 alpha2 | Vulnerable | parse-community |
| cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha3:*:*:*:node.js:*:* | 9.8.0 alpha3 | Vulnerable | parse-community |
| cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha4:*:*:*:node.js:*:* | 9.8.0 alpha4 | Vulnerable | parse-community |
| cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha5:*:*:*:node.js:*:* | 9.8.0 alpha5 | Vulnerable | parse-community |
- cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* Versions before 8.6.74; 9.0.0 to before 9.8.0 Vulnerable ·parse-community
- cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha1:*:*:*:node.js:*:* Versions 9.8.0 alpha1 Vulnerable ·parse-community
- cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha2:*:*:*:node.js:*:* Versions 9.8.0 alpha2 Vulnerable ·parse-community
- cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha3:*:*:*:node.js:*:* Versions 9.8.0 alpha3 Vulnerable ·parse-community
- cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha4:*:*:*:node.js:*:* Versions 9.8.0 alpha4 Vulnerable ·parse-community
- cpe:2.3:a:parseplatform:parse-server:9.8.0:alpha5:*:*:*:node.js:*:* Versions 9.8.0 alpha5 Vulnerable ·parse-community
Remediation
- Fix · CNA parse-server (parse-community) Fixed in 9.8.0-alpha.6, 8.6.74
- Fix · GHSA-mmpq-5hcv-hf2v parse-server (npm) Fixed in 9.8.0-alpha.6 Advisory →
- Fix · GHSA-mmpq-5hcv-hf2v parse-server (npm) Fixed in 8.6.74 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-39321
- 2026-10-03 Alias added: GHSA-mmpq-5hcv-hf2v
References
Patch 3
More parse-community Parse-server vulnerabilities
- TI-2022-08574 Command Injection in Parse server CVSS 3.1CRITICAL 10.0
- TI-2024-18136 Parse Server literalizeRegexPart SQL Injection CVSS 3.1CRITICAL 10.0
- TI-2022-18768 Parse Server vulnerable to Remote Code Execution via prototype pollution in MongoDB BSON parser CVSS 3.1CRITICAL 9.8
- TI-2024-31550 Parse Server's custom object ID allows to acquire role privileges CVSS 3.1HIGH 8.1
- TI-2023-18316 Parse Server vulnerable to remote code execution via MongoDB BSON parser through prototype pollution CVSS 3.1CRITICAL 9.8
- TI-2026-23790 Parse Server session token exfiltration via `redirectClassNameForKey` query parameter CVSS 4.0CRITICAL 9.9
Sources
- CVE-2026-39321 · CVE Program
- CVE-2026-39321 · NVD
- FIRST EPSS
- GHSA-mmpq-5hcv-hf2v · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences