CVE-2025-69873
Ajv Regular Expression Denial of Service (ReDoS)
Description
ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. This issue is also fixed in version 6.14.0.
INFO
Published Date :
Feb. 11, 2026, 7:15 p.m.
Last Modified :
March 2, 2026, 9:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Update ajv to version 8.17.2 or later.
- Disable the $data option in ajv configurations.
- Sanitize all input used in regex patterns.
- Avoid using dynamic schema validation with user input.
Public PoC/Exploit Available at Github
CVE-2025-69873 has a 7 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
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-2025-69873.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-69873 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-2025-69873
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).
This is a warrior's private repository, and every file in this repository belongs solely to me.
Shell
Hardened Playwright MCP implementation with Podman rootless containers, 5-stage gatekeeping strategy, and enterprise security controls
Dockerfile JavaScript
None
Security vulnerability disclosures and advisories by Ethan Taebeom Kim (Cremit)
Reasoning orchestration MCP server — Tree of Thoughts with deep planning, branching, and revision. Drop-in replacement for sequential-thinking with critical Claude Code string coercion fix. Works with Claude Code, Claude Desktop, and any MCP client.
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Dockerfile TypeScript JavaScript
# مستودع asrar-mared هذا هو المستودع الرئيسي لمجموعة **المارد الرقمي**، نقطة التحكم المركزية التي تجمع كل المشاريع والميول التقنية تحت راية واحدة. يمثل الأساس الذي تُبنى عليه الفروع الأخرى، ويُدار منه كل شيء من تنظيم الكود إلى إدارة المجتمع. للاطلاع على المستودع: [asrar-mared](https://github.com/asrar-mared)
HTML CSS
None
JavaScript TypeScript PowerShell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-69873 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-69873 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.
-
CVE Modified by [email protected]
Mar. 02, 2026
Action Type Old Value New Value Changed Description ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. This issue is also fixed in version 6.14.0. Added Reference https://github.com/ajv-validator/ajv/pull/2588 Added Reference https://github.com/ajv-validator/ajv/pull/2590 Added Reference https://github.com/ajv-validator/ajv/releases/tag/v6.14.0 Added Reference https://github.com/github/advisory-database/pull/6991 -
CVE Modified by [email protected]
Feb. 23, 2026
Action Type Old Value New Value Changed Description ajv (Another JSON Schema Validator) through version 8.17.1 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. ajv (Another JSON Schema Validator) before 8.18.0 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. Added CVSS V3.1 AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-1333 Added Reference https://github.com/advisories/GHSA-2g4f-4pwh-qvx6 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Feb. 12, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-400 -
New CVE Received by [email protected]
Feb. 11, 2026
Action Type Old Value New Value Added Description ajv (Another JSON Schema Validator) through version 8.17.1 is vulnerable to Regular Expression Denial of Service (ReDoS) when the $data option is enabled. The pattern keyword accepts runtime data via JSON Pointer syntax ($data reference), which is passed directly to the JavaScript RegExp() constructor without validation. An attacker can inject a malicious regex pattern (e.g., "^(a|a)*$") combined with crafted input to cause catastrophic backtracking. A 31-character payload causes approximately 44 seconds of CPU blocking, with each additional character doubling execution time. This enables complete denial of service with a single HTTP request against any API using ajv with $data: true for dynamic schema validation. Added Reference https://github.com/EthanKim88/ethan-cve-disclosures/blob/main/CVE-2025-69873-ajv-ReDoS.md