SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-26824

libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser.

MEDIUM 6.5EPSS 0.23%

Does this matter?

Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own.

Description

libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser. Memory allocated for the Master Sector Allocation Table (MSAT) in read_MSAT() is not fully initialized before being consumed by ole2_validate_sector_chain(), which may result in application crashes or potential information disclosure when processing a crafted XLS file

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
EPSS
0.23% probability · 14th percentile
CISA KEV
Not listed
Weakness
CWE-457
Affected
libxls project/libxls
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.