Heap-Based Buffer Overflow in Sparklemotion Nokogiri
CVE-2025-6494

4.8MEDIUM

Key Information:

Vendor

Sparklemotion

Status
Nokogiri
Vendor
CVE Published:
22 June 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-6494?

A significant vulnerability exists in Sparklemotion's Nokogiri library, specifically affecting the function hashmap_get_with_hash located in the file gumbo-parser/src/hashmap.c. This flaw allows for a heap-based buffer overflow, which can be exploited through local means. Given that the exploit has been disclosed publicly, it represents a potential risk to affected systems, particularly those running Nokogiri versions up to 1.18.7. Users and administrators are urged to assess their installations for this vulnerability and take appropriate measures.

Affected Version(s)

nokogiri 1.18.0

nokogiri 1.18.1

nokogiri 1.18.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-6494 - Proof of Concept

References

https://vuldb.com/?id.313611
vdb-entrytechnical-description
https://vuldb.com/?ctiid.313611
signaturepermissions-required
https://vuldb.com/?submit.601006
third-party-advisory

CVSS V4

Score:
4.8
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

JJLeo (VulDB User)
.
CVE-2025-6494 : Heap-Based Buffer Overflow in Sparklemotion Nokogiri