Parse Server: Pre-authentication denial of service via client version header regex backtracking
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-1333.
Summary
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.77 and 9.9.1-alpha.1, an unauthenticated attacker who knows a publicly-known Parse Application ID can submit a single HTTP request whose client SDK version field contains adversarial input that triggers polynomial backtracking in a request-header parser. The parsing runs before session authentication and before rate limiting on every /parse/* request, so the request consumes seconds to minutes of synchronous CPU on a Node.js worker before any access control evaluates it. A small number of concurrent requests can saturate a worker; a single large request via the body-field variant can pin a worker for minutes. Production deployments running the default configuration are affected. This issue has been patched in versions 8.6.77 and 9.9.1-alpha.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- 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 | before 8.6.77; 9.0.0 to before 9.9.1-alpha.1 | 8.6.77, 9.9.1-alpha.1 | Patch available | CNA |
| — | parse-server (npm) | 9.0.0 to before 9.9.1-alpha.1 | 9.9.1-alpha.1 | Patch available | GHSA-38m6-82c8-4xfm |
| — | parse-server (npm) | before 8.6.77 | 8.6.77 | Patch available | GHSA-38m6-82c8-4xfm |
- parse-server Vendorparse-community Affected before 8.6.77; 9.0.0 to before 9.9.1-alpha.1 Fixed in 8.6.77, 9.9.1-alpha.1 Patch available CNA
- parse-server (npm) Vendor— Affected 9.0.0 to before 9.9.1-alpha.1 Fixed in 9.9.1-alpha.1 Patch available GHSA-38m6-82c8-4xfm
- parse-server (npm) Vendor— Affected before 8.6.77 Fixed in 8.6.77 Patch available GHSA-38m6-82c8-4xfm
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:*:*:* | — | — | parse-community |
- cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:*:*:* Versions — — ·parse-community
Remediation
- Fix · CNA parse-server (parse-community) Fixed in 8.6.77, 9.9.1-alpha.1
- Fix · GHSA-38m6-82c8-4xfm parse-server (npm) Fixed in 9.9.1-alpha.1 Advisory →
- Fix · GHSA-38m6-82c8-4xfm parse-server (npm) Fixed in 8.6.77 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-47138
- 2026-10-03 Alias added: GHSA-38m6-82c8-4xfm
- 2026-10-25 EPSS moved to the below the 50th percentile
References
More parse-community 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-2025-35510 parse is a package designed to parse JavaScript SDK. CVSS 3.1MEDIUM 6.5
- TI-2024-26265 ZDI-CAN-23894: Parse Server literalizeRegexPart SQL Injection Authentication Bypass Vulnerability CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-47138 · CVE Program
- CVE-2026-47138 · NVD
- FIRST EPSS
- GHSA-38m6-82c8-4xfm · 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