xlnt-community xlnt up to 1.6.1 Encrypted XLSX File Parser base64.cpp decode_base64 off-by-one

Summaryinfo

A vulnerability identified as problematic has been detected in xlnt-community xlnt up to 1.6.1. The affected element is the function xlnt::detail::decode_base64 of the file source/detail/cryptography/base64.cpp of the component Encrypted XLSX File Parser. The manipulation leads to off-by-one. This vulnerability is traded as CVE-2026-2703. An attack has to be approached locally. Furthermore, there is an exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in xlnt-community xlnt up to 1.6.1 and classified as problematic. This issue affects the function xlnt::detail::decode_base64 of the file source/detail/cryptography/base64.cpp of the component Encrypted XLSX File Parser. The manipulation with an unknown input leads to a off-by-one vulnerability. Using CWE to declare the problem leads to CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. Impacted is availability.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-2703. The exploitation is known to be easy. An attack has to be approached locally. Technical details as well as a public exploit are known.

The exploit is available at github.com. It is declared as proof-of-concept.

Applying the patch f2d7bf494e5c52706843cf7eb9892821bffb0734 is able to eliminate this problem. The bugfix is ready for download at github.com.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 3.9

VulDB Base Score: 3.3
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CNA Base Score: 3.3
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Off-by-one
CWE: CWE-193 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: f2d7bf494e5c52706843cf7eb9892821bffb0734

Timelineinfo

02/18/2026 Advisory disclosed
02/18/2026 +0 days VulDB entry created
03/11/2026 +21 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 137
Status: Confirmed

CVE: CVE-2026-2703 (🔒)
GCVE (CVE): GCVE-0-2026-2703
GCVE (VulDB): GCVE-100-346649
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 02/18/2026 07:04 PM
Updated: 03/11/2026 02:17 AM
Changes: 02/18/2026 07:04 PM (60), 03/11/2026 02:17 AM (41)
Complete: 🔍
Submitter: Oneafter
Cache ID: 244::40

Submitinfo

Accepted

  • Submit #754377: xlnt-community xlnt 5606f5b Heap-based Buffer Overflow (by Oneafter)

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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