CVE-2026-2703
xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-one
- State
- Published
- Severity
- 4.8 Medium
- Published
- Feb 19, 2026
- Updated
- Feb 24, 2026
- Reserved
- Feb 18, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 4.8 Medium | 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 | VulDB |
| 3.1 | 3.3 Low | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C | VulDB |
| 3.0 | 3.3 Low | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C | VulDB |
| 2.0 | 1.7 Low | AV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:OF/RC:C | VulDB |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
xlntxlnt-community |
|
References
- VDB-346649 | xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-onevdb-entrytechnical-description
- VDB-346649 | CTI Indicators (IOB, IOC, IOA)signaturepermissions-required
- Submit #754377 | xlnt-community xlnt 5606f5b Heap-based Buffer Overflowthird-party-advisory
- https://github.com/xlnt-community/xlnt/issues/137issue-tracking
- https://github.com/oneafter/0128/blob/main/xl1/reproexploit
- https://github.com/xlnt-community/xlnt/commit/f2d7bf494e5c52706843cf7eb9892821bffb0734patch
- https://github.com/xlnt-community/xlnt/product
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