Vulnerability in XLSX File Parser of xlnt by xlnt-community
CVE-2026-3665

4.8MEDIUM

Key Information:

Vendor

Xlnt-community

Status
Xlnt
Vendor
CVE Published:
7 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-3665?

A vulnerability has been identified in xlnt-community's xlnt version 1.6.1 and earlier, specifically within the XLSX File Parser component. The issue arises in the function responsible for reading Office documents, where a null pointer dereference can occur. This vulnerability necessitates local access for exploitation, and there is an available public exploit that could potentially be utilized by malicious actors.

Affected Version(s)

xlnt 1.6.0

xlnt 1.6.1

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-2026-3665 - Proof of Concept

References

https://vuldb.com/?id.349554
vdb-entrytechnical-description
https://vuldb.com/?ctiid.349554
signaturepermissions-required
https://vuldb.com/?submit.764647
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

Oneafter (VulDB User)
.