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TI-2025-13782 Aliases CVE-2025-15104GHSA-fccg-7w3p-w66f

Nu Html Checker (validator.nu) - Restriction bypass vulnerability allowing local SSRF

Priority HIGH 70CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.

Summary

Nu Html Checker (validator.nu) contains a restriction bypass that allows remote attackers to make the server perform arbitrary HTTP/HTTPS requests to internal resources, including localhost services. While the validator implements hostname-based protections to block direct access to localhost and 127.0.0.1, these controls can be bypassed using DNS rebinding techniques or domains that resolve to loopback addresses.This issue affects The Nu Html Checker (vnu): latest (commit 23f090a11bab8d0d4e698f1ffc197a4fe226a9cd).

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00465 40th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
The Nu Html CheckerThe Nu Html Checkerlatest - commit:23f090a11bab8d0d4e698f1ffc197a4fe226a9cd—No fix listedCNA
—nu.validator:validator (Maven)up to 26.1.11—No fix listedGHSA-fccg-7w3p-w66f
—vnu-jar (npm)up to 26.1.11—No fix listedGHSA-fccg-7w3p-w66f
  • The Nu Html Checker VendorThe Nu Html Checker Affected latest - commit:23f090a11bab8d0d4e698f1ffc197a4fe226a9cd Fixed in — No fix listed CNA
  • nu.validator:validator (Maven) Vendor— Affected up to 26.1.11 Fixed in — No fix listed GHSA-fccg-7w3p-w66f
  • vnu-jar (npm) Vendor— Affected up to 26.1.11 Fixed in — No fix listed GHSA-fccg-7w3p-w66f

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:validator:validator:*:*:*:*:*:*:*:*before 2026-01-11VulnerableValidator
  • cpe:2.3:a:validator:validator:*:*:*:*:*:*:*:* Versions before 2026-01-11 Vulnerable ·Validator

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-15104
  2. 2026-10-03 Alias added: GHSA-fccg-7w3p-w66f

References

Exploit 1

Advisory 1

Other 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences