Tnef: heap buffer overflow in find_free_number() via numbered-backup suffix generation
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.
CVE-2026-103680
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-103680
Structured affected-version data
Original package identities and version rules from this source.
[
{
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver",
"lessThanOrEqual": "1.4.18"
}
],
"packageName": "tnef",
"collectionURL": "https://github.com/verdammelt/tnef",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-103680
Source reference:
/cveMetadata/cveId
Publisher severity
low
Source reference: /containers/cna/metrics
- Event
- #5304 · Revision 1
- Added to Heist Feed
- Publisher date