CVE-2026-103680

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

MEDIUM
6.5
CVSS Score
Published: October 1, 2026 at 11:34 AM UTC
Updated: October 5, 2026 at 01:42 PM UTC
1 product affected across 1 vendorTnef

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 1.4.18

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (3)

VDB Entryx_refsource_REDHATThird Party Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-103680
Issue Trackingx_refsource_REDHATThird Party Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2544478
Product
Source: cverecord
https://github.com/verdammelt/tnef

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-787

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