CVE-2026-26824

EUVD-2026-34178
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
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: 13.4%
Affected Products (NVD)
VendorProductVersion
libxls_projectlibxls
𝑥
≤ 1.6.3
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
r-cran-readxl
bookworm
postponed
bullseye
postponed
forky
vulnerable
sid
vulnerable
trixie
no-dsa
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
r-cran-readxl
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
ignored
resolute
needs-triage
xenial
needs-triage
Common Weakness Enumeration
References
https://github.com/libxls/libxls/issues/155
https://github.com/libxls/libxls/issues/155