CVE-2026-103679 Tnef: use-after-free and double-free in get_body_files() via multi-value body extraction
A remote attacker can cause a denial of service by sending a crafted TNEF file that triggers a use-after-free and double-free in the tnef library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-103679?
CVE-2026-103679 is a medium-severity use after free vulnerability in tnef_project:tnef, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A flaw was found in tnef. A remote attacker could exploit this vulnerability by providing a specially crafted Transport Neutral Encapsulation Format (TNEF) file containing multiple message bodies. During extraction, improper memory management triggers a use-after-free and double-free condition, causing the application to crash and resulting in a Denial of Service (DoS).
Weakness: CWE-416
Which versions are affected by CVE-2026-103679?
It affects 1 product.
Products include Tnef Project Tnef.
How do I fix CVE-2026-103679?
No fix has been published for CVE-2026-103679 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-103679 being exploited?
There is no known exploitation of CVE-2026-103679 in the wild and no public exploit code.
Other vulnerabilities in tnef_project:tnef
Sources
Also known as DEBIAN-CVE-2026-103679, GHSA-hh3v-7rq2-8fq9, UBUNTU-CVE-2026-103679.