CVE-2026-103680

Low

Description

A flaw was found in tnef. A heap-based buffer overflow can occur in the find_free_number() function when generating numbered backup suffixes for duplicate filenames. When numbered backups are enabled and file overwriting is disabled, an attacker can supply a specially crafted Transport Neutral Encapsulation Format (TNEF) file with an excessive number of colliding attachment filenames, causing the numeric counter to write past the allocated memory buffer. This issue may result in an application crash, leading to a Denial of Service (DoS), or potentially arbitrary code execution.

SeverityLow
CVSS3.1
Exploit probability—
ProductTnef
PublishedOct 1, 2026
First seenOct 1, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
tnef_project tnefv ≤ 1.4.18—

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CVE-2026-103680 · Tnef · Dark Radar