CVE-2026-103678
Tnef: heap out-of-bounds read in get_rtf_data_from_buf() via uncompressed rtf mapi value
Description
A flaw was found in tnef. An attacker can exploit this vulnerability by providing a specially crafted file containing uncompressed Rich Text Format (RTF) data. Because the application fails to properly validate input buffer boundaries before copying data in get_rtf_data_from_buf(), reading beyond the allocated memory occurs. This flaw can cause the application to crash, leading to a Denial of Service (DoS), or leak sensitive memory contents into extracted output files.
INFO
Published Date :
Oct. 1, 2026, 12:17 p.m.
Last Modified :
Oct. 5, 2026, 2:25 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 92fb86c3-55a5-4fb5-9c3f-4757b9e96dc5 | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Validate input buffer boundaries before copying data.
- Fix the get_rtf_data_from_buf function.
- Update the tnef application to the latest version.
- Apply vendor-supplied security patches.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-103678.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-103678 | Third Party Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2544476 | Issue Tracking Third Party Advisory |
| https://github.com/verdammelt/tnef | Product |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-103678 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-103678
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-103678 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-103678 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Oct. 05, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:tnef_project:tnef:*:*:*:*:*:*:*:* versions up to (including) 1.4.18 Added Reference Type Fedora Project: https://access.redhat.com/security/cve/CVE-2026-103678 Types: Third Party Advisory Added Reference Type Fedora Project: https://bugzilla.redhat.com/show_bug.cgi?id=2544476 Types: Issue Tracking, Third Party Advisory Added Reference Type Fedora Project: https://github.com/verdammelt/tnef Types: Product -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 01, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-103678', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-01T15:00:11.354180Z'} -
New CVE Received by [email protected]
Oct. 01, 2026
Action Type Old Value New Value Added Description A flaw was found in tnef. An attacker can exploit this vulnerability by providing a specially crafted file containing uncompressed Rich Text Format (RTF) data. Because the application fails to properly validate input buffer boundaries before copying data in get_rtf_data_from_buf(), reading beyond the allocated memory occurs. This flaw can cause the application to crash, leading to a Denial of Service (DoS), or leak sensitive memory contents into extracted output files. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L Added CWE CWE-125 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/103xxx/CVE-2026-103678.json">CVE-2026-103678</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-103678 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2544476 Added Reference https://github.com/verdammelt/tnef