CVE-2026-2703

xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-one

MEDIUM
5.5
CVSS Score
Published: February 19, 2026 at 04:02 AM UTC
Updated: June 17, 2026 at 10:31 AM UTC
1 product affected across 1 vendorXlnt

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (7)

VDB EntryTechnical DescriptionThird Party Advisory
Source: cverecord
https://vuldb.com/?id.346649
SignaturePermissions RequiredVDB Entry
Source: cverecord
https://vuldb.com/?ctiid.346649
Third Party AdvisoryVDB Entry
Source: cverecord
https://vuldb.com/?submit.754377
Issue TrackingExploitVendor Advisory
Source: cverecord
https://github.com/xlnt-community/xlnt/issues/137

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-193CWE-189

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