9.8
CRITICAL CVSS 3.1
CVE-2026-45185
Exim GnuTLS Use-After-Free Remote Code Execution Vulnerability
Description

Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.

INFO

Published Date :

May 12, 2026, 8:16 p.m.

Last Modified :

May 12, 2026, 9:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-45185 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update Exim to version 4.99.3 or later to fix heap corruption and arbitrary code execution vulnerabilities.
  • Update Exim to version 4.99.3 or later.
  • Verify GnuTLS configuration settings.
  • Monitor network traffic for suspicious activity.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-45185 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-2026-45185 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-2026-45185 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-45185 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.

  • CVE Modified by [email protected]

    May. 12, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-416
  • New CVE Received by [email protected]

    May. 12, 2026

    Action Type Old Value New Value
    Added Description Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.
    Added Reference https://code.exim.org/exim/wiki/wiki/EximSecurity
    Added Reference https://exim.org
    Added Reference https://exim.org/static/doc/security/CVE-2026-45185.txt
    Added Reference https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/
    Added Reference https://news.ycombinator.com/item?id=48111748
    Added Reference https://www.openwall.com/lists/oss-security/2026/05/12/4
    Added Reference https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.