7.7
HIGH CVSS 4.0
CVE-2025-12758
Validator Package Unicode Filtering Vulnerability
Description

Versions of the package validator before 13.15.22 are vulnerable to Incomplete Filtering of One or More Instances of Special Elements in the isLength() function that does not take into account Unicode variation selectors (\uFE0F, \uFE0E) appearing in a sequence which lead to improper string length calculation. This can lead to an application using isLength for input validation accepting strings significantly longer than intended, resulting in issues like data truncation in databases, buffer overflows in other system components, or denial-of-service.

INFO

Published Date :

Nov. 27, 2025, 5:16 a.m.

Last Modified :

Nov. 27, 2025, 5:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2025-12758 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH [email protected]
Solution
Update the validator package to a version that includes fixes for string length calculation issues.
  • Update the validator package to version 13.15.22 or later.
  • Verify input validation logic for Unicode characters.
  • Test for potential data truncation or buffer overflows.
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-2025-12758.

URL Resource
https://gist.github.com/koral--/ad31208b25b9e3d1e2e35f1d4d72572e
https://github.com/validatorjs/validator.js/pull/2616
https://security.snyk.io/vuln/SNYK-JS-VALIDATOR-13653476
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-12758 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-2025-12758 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-2025-12758 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-12758 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.

  • New CVE Received by [email protected]

    Nov. 27, 2025

    Action Type Old Value New Value
    Added Description Versions of the package validator before 13.15.22 are vulnerable to Incomplete Filtering of One or More Instances of Special Elements in the isLength() function that does not take into account Unicode variation selectors (\uFE0F, \uFE0E) appearing in a sequence which lead to improper string length calculation. This can lead to an application using isLength for input validation accepting strings significantly longer than intended, resulting in issues like data truncation in databases, buffer overflows in other system components, or denial-of-service.
    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:P/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 CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-792
    Added Reference https://gist.github.com/koral--/ad31208b25b9e3d1e2e35f1d4d72572e
    Added Reference https://github.com/validatorjs/validator.js/pull/2616
    Added Reference https://security.snyk.io/vuln/SNYK-JS-VALIDATOR-13653476
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 7.7
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 7.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact