validator: Incomplete Filtering of One or More Instances of Special Elements
CVE-2025-12758 is a high-severity incomplete filtering of one or more instances of special elements vulnerability in validator, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 13.15.22 as the first without the flaw, so updating validator to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.55% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update validator to 13.15.22 or a later version.
- Update org.webjars.npm:validator to 13.15.22 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Validator | validator | before 13.15.22 | 13.15.22 |
| Org.webjars.npm:validator | org.webjars.npm:validator | before 13.15.22 | 13.15.22 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (snyk.io).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.7 | High | CNA (snyk.io) |
| CVSS 3.1 | 7.5 | High | CNA (snyk.io) |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incomplete Filtering of One or More Instances of Special Elements
The product receives data from an upstream component, but does not completely filter one or more instances of special elements before sending it to a downstream component.
More Incomplete Filtering of One or More Instances of Special Elements vulnerabilities (CWE-792)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/validatorjs/validator.js/pull/2616Issue Tracking
Technical write-ups (may include proof of concept)
- gist.github.com/koral--/ad31208b25b9e3d1e2e35f1d4d72572eExploit, Third Party Advisory
- security.snyk.io/vuln/SNYK-JS-VALIDATOR-13653476Exploit, Third Party Advisory
Other references
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