Vulnerability · Published Feb 19, 2026 · Assigned by VulDB
CVE-2026-2703xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-one
Low 3.3
In plain English
A low-severity security flaw in xlnt from xlnt-community. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| xlnt-community | xlnt | 1.6.01.6.1 |
Weakness: CWE-193, CWE-189 · Vector: 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
References
- VDB-346649 | xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-one vdb-entry, technical-description
- VDB-346649 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- Submit #754377 | xlnt-community xlnt 5606f5b Heap-based Buffer Overflow third-party-advisory
- https://github.com/xlnt-community/xlnt/issues/137 issue-tracking
- https://github.com/oneafter/0128/blob/main/xl1/repro exploit
- https://github.com/xlnt-community/xlnt/commit/f2d7bf494e5c52706843cf7eb9892821bffb0734 patch
- https://github.com/xlnt-community/xlnt/ product