libxls 1.6.3 XLS File Parser xls_parseWorkBook uninitialized pointer

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.4	$0-$5k	0.00

Summaryinfo

A vulnerability identified as critical has been detected in libxls 1.6.3. This impacts the function xls_parseWorkBook of the component XLS File Parser. Performing a manipulation results in uninitialized pointer. This vulnerability was named CVE-2026-26825. There is no available exploit.

Detailsinfo

A vulnerability was found in libxls 1.6.3. It has been classified as critical. This affects the function xls_parseWorkBook of the component XLS File Parser. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. CWE is classifying the issue as CWE-824. The product accesses or uses a pointer that has not been initialized. The impact remains unknown. The summary by CVE 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.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-26825 since 02/16/2026. The exploitability is told to be easy. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 318860 (Linux Distros Unpatched Vulnerability : CVE-2026-26825), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (318860) and EUVD (EUVD-2026-34179). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

libxls

Version

1.6.3

Website

Product: https://github.com/libxls/libxls/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔒

ADP CISA Base Score: 5.3
ADP CISA Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Uninitialized pointer
CWE: CWE-824 / CWE-908
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
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Nessus ID: 318860
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-26825

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

02/16/2026 CVE reserved
06/03/2026 +106 days Advisory disclosed
06/03/2026 +0 days VulDB entry created
06/08/2026 +5 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 156
Status: Confirmed

CVE: CVE-2026-26825 (🔒)
GCVE (CVE): GCVE-0-2026-26825
GCVE (VulDB): GCVE-100-368223
EUVD: 🔒

Entryinfo

Created: 06/03/2026 22:41
Updated: 06/08/2026 23:22
Changes: 06/03/2026 22:41 (53), 06/04/2026 00:26 (1), 06/06/2026 08:53 (2), 06/08/2026 09:57 (11), 06/08/2026 23:22 (9)
Complete: 🔍
Cache ID: 216::103