VDB-370937 · CVE-2026-6040 · Nessus 321128

LibreOffice up to 25.8.6/26.2.2 use after free

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.
6.0	$0-$5k	0.00

Summaryinfo

A vulnerability was found in LibreOffice up to 25.8.6/26.2.2. It has been rated as critical. The affected element is an unknown function. The manipulation leads to use after free. This vulnerability is uniquely identified as CVE-2026-6040. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in LibreOffice up to 25.8.6/26.2.2. This issue affects an unknown function. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.

The weakness was disclosed by Anthropic. The advisory is shared at libreoffice.org. The identification of this vulnerability is CVE-2026-6040 since 04/09/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 321128 (Debian dsa-6346 : fonts-opensymbol - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 25.8.7 or 26.2.3 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (321128) and CERT Bund (WID-SEC-2026-1929). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

Debian Linux
Red Hat Enterprise Linux
RESF Rocky Linux
SUSE Linux
Open Source LibreOffice
Ubuntu Linux
Oracle Linux

Productinfo

Type

Office Suite Software

Name

LibreOffice

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 321128
Nessus Name: Debian dsa-6346 : fonts-opensymbol - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: LibreOffice 25.8.7/26.2.3

Timelineinfo

04/09/2026 CVE reserved
06/15/2026 +67 days Advisory disclosed
06/15/2026 +0 days VulDB entry created
07/21/2026 +36 days VulDB entry last update

Sourcesinfo

Advisory: libreoffice.org
Researcher: Anthropic
Status: Confirmed

CVE: CVE-2026-6040 (🔒)
GCVE (CVE): GCVE-0-2026-6040
GCVE (VulDB): GCVE-100-370937
CERT Bund: WID-SEC-2026-1929 - LibreOffice: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Entryinfo

Created: 06/15/2026 21:12
Updated: 07/21/2026 11:56
Changes: 06/15/2026 21:12 (67), 06/16/2026 08:05 (2), 07/03/2026 03:16 (1), 07/16/2026 12:37 (7), 07/21/2026 11:56 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.