CVE-2026-26825

Name: CVE-2026-26825
Creator: NVD / NIST
Published: 2026-06-03T20:16:18.797+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.21%

Last modified Jun 17, 2026

CVE-2026-26825 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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). EPSS estimates a 0.21% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.21%

11.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Libxls Project	Libxls	1.6.3

References

https://github.com/libxls/libxls/issues/156Exploit, Issue Tracking

Timeline

Published: Jun 3, 2026
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2026-26825?

How severe is CVE-2026-26825?

CVE-2026-26825 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2026-26825?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-26825?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST