Symlink Following Vulnerability in SparkJava by perwendel
CVE-2026-17459

5.3MEDIUM

Key Information:

Vendor

Perwendel

Status
Spark
Vendor
CVE Published:
26 July 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-17459?

A vulnerability identified in the SparkJava framework up to version 2.9.4 relates to the staticFiles.externalLocation function. This issue allows an attacker to exploit the symlink following behavior within the ExternalResourceHandler component. The flaw can be exploited remotely, posing a significant risk to systems using this version of SparkJava. It was acknowledged through an early report, but the project maintainers have yet to respond to the issue publicly. Security best practices should be followed to mitigate potential impacts until a patch is released.

Affected Version(s)

spark 2.9.0

spark 2.9.1

spark 2.9.2

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-2026-17459 - Proof of Concept

References

https://vuldb.com/vuln/383321
vdb-entrytechnical-description
https://vuldb.com/vuln/383321/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-17459
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
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

naixiao (VulDB User)
VulDB CNA Team
.