CVE-2026-6040

Memory corruption via unchecked ODF blank-width position

Published Jun 15, 2026 · Updated Jun 15, 2026

Heap use-after-free in LibreOffice 25.8 before 25.8.7 and 26.2 before 26.2.3 allows local users to corrupt memory via a crafted ODF file. The ODF number-format importer accepts a document-supplied blank-width position without checking it against the format-code string length, then processes memory outside that string. A victim must open the crafted document; the resulting stale-pointer access can corrupt process memory and interrupt the LibreOffice session.

CVSS severity7.3
High
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap use-after-free in LibreOffice 25.8 before 25.8.7 and 26.2 before 26.2.3 allows local users to corrupt memory via a crafted ODF file. The ODF number-format importer accepts a document-supplied blank-width position without checking it against the format-code string length, then processes memory outside that string. A victim must open the crafted document; the resulting stale-pointer access can corrupt process memory and interrupt the LibreOffice session.

The record

CVE
CVE-2026-6040
Published
Jun 15, 2026
Updated
Jun 15, 2026
Vendor
The Document Foundation
Product
LibreOffice
Classifications
CWE-825, CWE-787, CWE-416, CAPEC-44, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=25.8 << 25.8.7
  2. Affected versionversion=26.2 << 26.2.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Document Foundation · LibreOfficeversion=25.8 << 25.8.7; version=26.2 << 26.2.3

Published CVSS scores

7.3Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
5.4The Document FoundationCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
CWE-787Out-of-bounds Write
CWE-416Use After Free
CAPEC-44Overflow Binary Resource File
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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