Is CVE-2026-3663 actively exploited?

CVE-2026-3663 has no public evidence of in-the-wild exploitation as of 2026-04-29.

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

CVE-2026-3663 has a CVSS score of 1.9 (LOW severity). Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

How do I patch CVE-2026-3663?

Patch guidance is available from xlnt-community security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-3663.

Which products are affected by CVE-2026-3663?

1 product: xlnt-community xlnt.

CVE-2026-3663 - remediation guidance & executive summary

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.

CVSS Metrics

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector: local
Complexity: low
Privileges: low
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-119 · Memory Buffer Errors CWE-125 · Out-of-bounds Read

Metadata

Primary Vendor: XLNT-COMMUNITY
Published: 3/7/2026
Last Modified: 4/29/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

CVE-2026-3663

Description

CVSS Metrics

Metadata

Affected Products

Remediation Guidance

Executive Summary