CVE-2026-26825CWE-908

CVE-2026-26825

Medium · published June 4, 2026

CVSS v3.1
5.3
EPSS
0%
Percentile
33.2
In the wild
Unconfirmed
What it is

A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00401 · 33.2th percentile
Weakness
CWE-908 · Use of Uninitialized Resource
Published
2026-06-04T00:16Z
Affected products (1)
ProductVersionsFixed in
libxls_project/libxlsall versions—
References (3)
https://github.com/libxls/libxls/commit/9adf88f4e3b304e397f70ac189e70776edb6d5a3 · [email protected]https://github.com/libxls/libxls/issues/153 · [email protected]https://github.com/libxls/libxls/issues/156 · [email protected]
EPSS history
Timeline
  • 03 JUN 00:00Z
    A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files
    cvelistv5