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CVE-2025-12758: Versions of the package validator before 13.15.22 are vulnerable to Incomplete Filtering of One or More Ins...

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.

HighCVSS 8.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2025-12758 affects the widely used validator package. Its isLength() check can miscount strings containing Unicode variation selectors, letting inputs pass length limits when they should not. Business impact depends on where applications rely on this validation, but possible outcomes include database truncation, downstream component failures, or denial-of-service.

Executive priority

Prioritize remediation for internet-facing applications and services where validator enforces input size limits. This is high severity but not confirmed as actively exploited from the provided sources. Treat it as a dependency hygiene and resilience issue with potential availability impact.

Technical view

validator versions before 13.15.22, including org.webjars.npm:validator, have incomplete filtering in isLength(). Unicode variation selectors \uFE0F and \uFE0E in a sequence are not accounted for correctly, causing improper length calculation. The CVE lists CVSS 4.0 score 8.7 high, network exploitable, low complexity, no privileges, no user interaction.

Likely exposure

Exposure is likely in JavaScript or Java/WebJars applications that use validator isLength() as a security or data-integrity control for user-supplied input. Risk is higher where accepted data later reaches strict database columns, parsers, buffers, or resource-constrained services.

Exploitation context

The CVE is not listed in KEV in the provided bundle. Sources include a public gist and a GitHub pull request, suggesting public technical detail exists, but the bundle does not establish active exploitation in the wild.

Researcher notes

Key weakness is Unicode-aware length validation, not classic injection. Focus assessment on trust boundaries where isLength() is the primary gate before storage, serialization, parsing, or native/downstream processing. Avoid assuming impact unless the application relies on validator length checks for security or resource control.

Mitigation direction

  • Upgrade validator to 13.15.22 or later where used directly.
  • Upgrade org.webjars.npm:validator to a non-vulnerable release.
  • Inventory transitive dependencies that include validator before 13.15.22.
  • Review vendor and Snyk advisories for package-specific remediation guidance.
  • Add defense-in-depth length checks at storage and service boundaries.

Validation and detection

  • Search dependency manifests and lockfiles for validator versions below 13.15.22.
  • Check Java builds for org.webjars.npm:validator usage.
  • Identify code paths using isLength() on untrusted input.
  • Confirm upgraded builds resolve to fixed package versions.
  • Review logs for unusual oversized inputs or truncation errors.
Prepared
Confidence
high
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-172: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cwe · low confidence lookup

CWE-792: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2025-12758 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.7 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
3Timeline events
2ADP providers
5Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.7CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P——snyk
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P3.93.6snyk

Vulnerability scoring details

Base CVSS 4.0 score

8.7High
CVSS 4.0 vector shape for CVE-2025-12758Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/avalidator0Listed
n/aorg.webjars.npm:validator0Listed
Weakness

CWE details

CWE-172CWE-792

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-172 · source CWE mapping

Encoding Error

Encoding Error represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-792 · source CWE mapping

Incomplete Filtering of One or More Instances of Special Elements

Incomplete Filtering of One or More Instances of Special Elements represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs