CVE-2026-47138
Parse Server: Pre-authentication denial of service via client version header regex backtracking
Description
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.
INFO
Published Date :
June 12, 2026, 7:16 p.m.
Last Modified :
June 12, 2026, 7:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Parse Server to version 8.6.77 or later.
- Update Parse Server to version 9.9.1-alpha.1 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-47138.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-47138 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-47138
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-47138 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-47138 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Jun. 12, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-1333 Added Reference https://github.com/parse-community/parse-server/pull/10463 Added Reference https://github.com/parse-community/parse-server/pull/10464 Added Reference https://github.com/parse-community/parse-server/security/advisories/GHSA-38m6-82c8-4xfm