---
id: CVE-2025-12758
title: >-
  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)…
summary: >-
  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)…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-792
  - CWE-172
vendor: validator_project
product: validator
affected:
  - validator < 13.15.22
patched:
  - validator 13.15.22
published: '2025-11-27'
updated: '2026-07-14'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-12758'
references:
  - url: 'https://gist.github.com/koral--/ad31208b25b9e3d1e2e35f1d4d72572e'
    label: report@snyk.io
  - url: 'https://github.com/validatorjs/validator.js/pull/2616'
    label: report@snyk.io
  - url: 'https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-14152011'
    label: report@snyk.io
  - url: 'https://security.snyk.io/vuln/SNYK-JS-VALIDATOR-13653476'
    label: report@snyk.io
  - url: 'http://seclists.org/fulldisclosure/2026/Jan/27'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.snyk.io/vuln/SNYK-JS-VALIDATOR-13653476'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - exploit-available
epss: 0.00517
epssPercentile: 0.41535
ingestedAt: '2026-07-15T13:44:03.505Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/open-flaw/CVE-2025-12758'
  checkedAt: '2026-09-26T09:05:32.835Z'
exploitAvailable: true
---

## Overview

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.

## Affected

- `validator < 13.15.22`

## Remediation

Upgrade past the affected range:

- `validator 13.15.22`