All vulnerabilities
CVE-2026-103680

Tnef: heap buffer overflow in find_free_number() via numbered-backup suffix generation

Unknown product
Open in ThreatlineRecord JSON
CVSS
3.1Low
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.33%Chance of exploitation activity in the next 30 days, higher than 24% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published1 Oct 2026Updated 1 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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.

Text from CVE List

Affected versions 1

  • Productaffected: all versions through 1.4.18CVE List

References 3