CVE-2026-103679: A flaw was found in tnef

Q: How do I fix CVE-2026-103679?

tnef: upgrade to newer than 1.4.18. Exact commands for each OS are on this page.

Q: Is CVE-2026-103679 being exploited?

CVE-2026-103679 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-103679 affect?

CVE-2026-103679 affects tnef. Severity is medium (CVSS 6.5). 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 manageme

Q: How urgent is CVE-2026-103679?

Priority 28/100. No elevated risk signals yet.

Routine

MEDIUM 6.5UPGRADE

CVE-2026-103679 is a medium-severity flaw (CVSS 6.5) affecting tnef. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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).

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 80%)
CISA exploited list	No
Weakness	CWE-416
Published	2026-10-01
Last modified	2026-10-05

Publisher (CNA): Fedora Project · Vendor: tnef project

Last updated 2026-10-05 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-01 12:17 UTCPublished CVE record published
2026-10-05 14:05 UTCUpdated Record last modified

tnef project tnef UPGRADE

Affected: <= 1.4.18

Fixed in: newer than 1.4.18

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy tnef || rpm -q tnef || tnef --version

2. UPGRADE to newer than 1.4.18 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade tnef

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tnef

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-103679?

tnef: upgrade to newer than 1.4.18. Exact commands for each OS are on this page.

Is CVE-2026-103679 being exploited?

CVE-2026-103679 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-103679 affect?

CVE-2026-103679 affects tnef. Severity is medium (CVSS 6.5). 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 manageme

How urgent is CVE-2026-103679?

Priority 28/100. No elevated risk signals yet.

Related CVEs

CVE-2026-103678 MEDIUM 5.4 UPGRADE A flaw was found in tnef
CVE-2026-103680 LOW 3.1 UPGRADE A flaw was found in tnef

References

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