CVE-2025-69873
Description
A flaw was found in ajv. When the $data option is enabled, the value of the pattern keyword is passed directly to the JavaScript RegExp() constructor without sufficient validation. An attacker able to supply a malicious regular expression pattern can trigger a ReDoS (Regular Expression Denial of Service), causing the application to become unresponsive and resulting in a denial of service.
Statement
To exploit this issue, the $data option must be enabled and the attacker needs to be able to send a payload with a specially crafted regular expression to the application processing the input. A 31-character payload causes approximately 44 seconds of execution, with each additional character doubling the execution time. Therefore, even a small payload can cause an application to become unresponsive and eventually result in a denial of service. Due to this reason, this flaw has been rated with an important severity.
Mitigation
To mitigate this issue, disable the $data feature if your application does not require it. If $data must be used, implement strict validation of the input fields that are referenced by the pattern keyword to ensure they contain only expected and safe characters.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Attackers can create crafted inputs that intentionally cause the regular expression to use excessive backtracking in a way that causes the CPU consumption to spike.
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