CVE-2026-63275Hinoki check available

Stack buffer overflow via unchecked glyph hints

Published Sep 22, 2026 · Updated Sep 22, 2026

Stack buffer overflow in The Document Foundation LibreOffice 26.2 before 26.2.5 allows attackers to corrupt memory via a crafted CFF font. The glyph hint reader checks a file-supplied hint count against the wrong bound, then writes beyond its fixed-size stack array. A victim must open a document containing the crafted font; the overwrite can crash LibreOffice or alter data in its process.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stack buffer overflow in The Document Foundation LibreOffice 26.2 before 26.2.5 allows attackers to corrupt memory via a crafted CFF font. The glyph hint reader checks a file-supplied hint count against the wrong bound, then writes beyond its fixed-size stack array. A victim must open a document containing the crafted font; the overwrite can crash LibreOffice or alter data in its process.

The record

CVE
CVE-2026-63275
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
The Document Foundation
Product
LibreOffice
Classifications
CWE-787, CAPEC-44, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 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=26.2 << 26.2.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Document Foundation · LibreOfficeversion=26.2 << 26.2.5

Published CVSS scores

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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