An integer underflow has been identified in the unicode_to_utf8() function in tnef 1.4.14. This might lead to invalid write operations, controlled by an attacker.
Conclusion & alert: CVE-2017-8911 is rated Moderate Risk (54.6/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.22%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-04-11 | 0.38% | 0.22% | -0.16% |
| 2 | 2025-03-30 | 1.21% | 0.38% | -0.83% |
| 3 | 2025-03-29 | — | 1.21% | — |
Full EPSS history (8 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.0 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 7.5 | 2.0 | HIGH |
|
10.0 | 6.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2017-8911 not yet assigned priority: Debian including 1 source packages (tnef), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2017-8911 |
gentoo
|
normal | CVE-2017-8911: 1 GLSA(s) (201708-02), 1 atom(s) (net-mail/tnef); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2017-8911 |
ubuntu
|
medium | CVE-2017-8911 medium priority: Ubuntu including 1 source packages (tnef), 5 status rows across 5 suites (trusty, upstream, xenial, yakkety, zesty): released 4, needs-triage 1. | https://ubuntu.com/security/CVE-2017-8911 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| tnef_project | tnef | 1.4.14 | cpe:2.3:a:tnef_project:tnef:1.4.14:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| http://www.debian.org/security/2017/dsa-3869 | |
| https://github.com/verdammelt/tnef/issues/23 | Issue Tracking Patch Third Party Advisory |
| https://security.gentoo.org/glsa/201708-02 |