CVE-2026-63272: Heap buffer overflow in WMF text record import

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.2%

EPSS score, percentile 10.4 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

5.4 Medium

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• from 26.2 to before < 26.2.5

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: unknown.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

LibreOffice can import WMF graphics, which may be embedded in documents. A heap buffer overflow existed when importing a text record that carries its own character advance widths. The count of advance values and the length of the text were read separately from the file and were not required to agree, so drawing the text walked the advance array by character position and ran past its end when the…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-63272 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 22 Sep 2026.
• The CVE record carries a CVSS v4.0 base score of 5.4 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 10.4), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

Heap buffer overflow in WMF text record import

LibreOffice can import WMF graphics, which may be embedded in documents. A heap buffer overflow existed when importing a text record that carries its own character advance widths. The count of advance values and the length of the text were read separately from the file and were not required to agree, so drawing the text walked the advance array by character position and ran past its end when the array was the shorter of the two. In fixed versions an advance array shorter than its text is ignored.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline