CVE-2026-107570: Use of Out-of-range Pointer Offset in mutt

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%

Up from 0.1% on 22 Oct 2026.

EPSS score, percentile 4.3 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

2.5 Low

CVSS v3.1 base score, given by the CNA

What should I do?

Upgrade to 2.4.3Solution from the CVE record.

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

• 2.4.2 and earlier

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

Solution (from the CVE record)

Upgrade to 2.4.3

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

heap OOB write in convert_file_from_to() via a crafted Content-Type header allows attacker to OOB write when email is used as a template.

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-107570 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 8 Oct 2026.
• The CVE record carries a CVSS v3.1 base score of 2.5 (Low), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 4.3), 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

Use of Out-of-range Pointer Offset in mutt

heap OOB write in convert_file_from_to() via a crafted Content-Type header allows attacker to OOB write when email is used as a template.

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

Timeline