CVE-2026-40687

CRITICAL EPSS 29.1%
Published Apr 30, 20262mo ago · Modified Jun 17, 20261w ago
9.1 CVSS 3.1
Critical
Find Similar
Published Apr 30, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

Description

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory.

CVSS Details

Base Score
9.1
Exploitability
3.9
Impact
5.2
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
29.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-909

Affected Products 1

VendorProductVersionRange
eximexim* <4.99.2

References 4

  • code.exim.org https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
    Patch
  • exim.org https://exim.org/static/doc/security/CVE-2026-40687.txt
    Broken Link
  • exim.org https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
    Vendor Advisory
  • openwall.com https://www.openwall.com/lists/oss-security/2026/04/30/21
    Mailing ListThird Party Advisory

Remediation

  • code.exim.org https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
    Patch