Is CVE-2026-3663 actively exploited?

No active exploitation of CVE-2026-3663 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-3663 be exploited remotely?

No. CVE-2026-3663 requires local access to exploit.

What is the CVSS score of CVE-2026-3663?

CVE-2026-3663 has a CVSS score of 7.1 (HIGH).

HOME VULNERABILITIESCVE-2026-3663

HIGH

CVE-2026-3663

CWE-119Published: March 7, 2026· Updated: Mar 10, 2026

7.1

CVSS v3.1

EPSS:0.01%probability of exploitation in 30 daysPercentile:2.0th

Official Description

A vulnerability was found in xlnt-community xlnt up to 1.6.1. This issue affects the function xlnt::detail::compound_document_istreambuf::xsgetn of the file source/detail/cryptography/compound_document.cpp of the component XLSX File Parser. Performing a manipulation results in out-of-bounds read. The attack is only possible with local access. The exploit has been made public and could be used. The patch is named 147. It is recommended to apply a patch to fix this issue.

NVD Source

Technical Analysis

CVE-2026-3663 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), availability disruption (denial of service), with a CVSS base score of 7.1.

From a weakness classification perspective (CWE-119): Buffer overflow vulnerabilities can lead to arbitrary code execution or denial of service by corrupting adjacent memory.