CVE-2026-103680: A flaw was found in tnef. A heap-based buffer overflow can occur in the find_free_number() function when generating…
CVE-2026-103680 · Severity: low · CVSS 3.1 · Published 2026-10-01
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.
No. Junglewise Threat Intelligence has no report of CVE-2026-103680 being exploited in the wild.
How severe is CVE-2026-103680?
Low severity, with a CVSS score of 3.1, published 1 October 2026.
Which products and versions are affected?
Tnef Project Tnef. The advisory does not name versions.
Is there a fix for CVE-2026-103680?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-103680?
Check whether you run Tnef Project Tnef. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.