CVE-2026-2703 MEDIUM

CVE-2026-2703: xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-one

Vendor Xlnt-Community
Product xlnt
Weakness CWE-193
Published February 19, 2026
Last update February 24, 2026

CVSS base score

4.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS 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

What the vulnerability does

01Description

A weakness has been identified in xlnt-community xlnt up to 1.6.1. Impacted is the function xlnt::detail::decode_base64 of the file source/detail/cryptography/base64.cpp of the component Encrypted XLSX File Parser. Executing a manipulation can lead to off-by-one. The attack requires local access. The exploit has been made available to the public and could be used for attacks. This patch is called f2d7bf494e5c52706843cf7eb9892821bffb0734. Applying a patch is advised to resolve this issue.

Key dates

02Disclosure timeline

February 19, 2026 CVE published
February 24, 2026 Record updated