---
id: CVE-2025-67896
title: >-
  Exim before 4.99.1, with certain non-default rate-limit configurations, allows
  a remote heap-based buffer overflow because database records are cast directly
  to internal structures without validation.
summary: >-
  Exim before 4.99.1, with certain non-default rate-limit configurations, allows
  a remote heap-based buffer overflow because database records are cast directly
  to internal structures without validation.
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L'
cwe:
  - CWE-122
vendor: exim
product: exim
affected:
  - exim < 4.99.1
patched:
  - exim 4.99.1
published: '2025-12-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-67896'
references:
  - url: 'https://exim.org/static/doc/security/'
    label: cve@mitre.org
  - url: 'https://exim.org/static/doc/security/EXIM-Security-2025-12-09.1/report.txt'
    label: cve@mitre.org
  - url: 'https://www.openwall.com/lists/oss-security/2025/12/11/2'
    label: cve@mitre.org
  - url: 'http://www.openwall.com/lists/oss-security/2025/12/14/1'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'http://www.openwall.com/lists/oss-security/2025/12/18/3'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.0047
epssPercentile: 0.38906
ingestedAt: '2026-10-14T13:30:58.423Z'
---

## Overview

Exim before 4.99.1, with certain non-default rate-limit configurations, allows a remote heap-based buffer overflow because database records are cast directly to internal structures without validation.

## Affected

- `exim < 4.99.1`

## Remediation

Upgrade past the affected range:

- `exim 4.99.1`