CVE-2026-94055Network attack vectorHinoki check available

Remote receive-process crash via GnuTLS use-after-free

Published Sep 19, 2026 · Updated Sep 19, 2026

Use-after-free in Exim 4.98 through 4.100 allows remote attackers to crash a receive process through TLS-on-connect. The GnuTLS TLS-on-connect path can continue using freed data when tls_early_banner_hosts is enabled, and corrected control flow avoids that access. Exploitation requires GnuTLS 3.6.4 or later, TLS-on-connect, and the non-default tls_early_banner_hosts setting; the bounded impact is one receive-process crash.

CVSS severity3.7
Low
EPSS probability0.29%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
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Summary

What happened

Use-after-free in Exim 4.98 through 4.100 allows remote attackers to crash a receive process through TLS-on-connect. The GnuTLS TLS-on-connect path can continue using freed data when tls_early_banner_hosts is enabled, and corrected control flow avoids that access. Exploitation requires GnuTLS 3.6.4 or later, TLS-on-connect, and the non-default tls_early_banner_hosts setting; the bounded impact is one receive-process crash.

The record

CVE
CVE-2026-94055
Published
Sep 19, 2026
Updated
Sep 19, 2026
Vendor
LibSPF2 Project
Product
Exim
Classifications
CWE-416, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.98 <4.100.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LibSPF2 Project · Eximversion=4.98 <4.100.1

Published CVSS scores

3.7MITRECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

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