CVE-2026-26825 Information disclosure in n/a

Medium 5.3 Published 3 Jun 2026 Updated 23 Sep 2026

Attackers can exploit uninitialized memory in libxls to potentially disclose sensitive information when parsing malformed XLS files.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-26825?

CVE-2026-26825 is a medium-severity vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-908

Which versions are affected by CVE-2026-26825?

It affects 1 product.

Products include Libxls Project Libxls.

How do I fix CVE-2026-26825?

Upgrade to a fixed version.

Is CVE-2026-26825 being exploited?

There is no known exploitation of CVE-2026-26825 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2026-26825, GHSA-48jr-3rh3-95w6, UBUNTU-CVE-2026-26825.