CVE-2026-40687CRITICAL 9.1EPSS p28.9%

CVE-2026-40687CVE-2026-40687

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.

Scoring

CVSS 3.19.1 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS0.37% probability of exploitation · percentile 28.9% · 2026-06-18T12:00:27Z
Published2026-04-30
Last modified2026-05-01

Underlying weaknesses· 1

CWE-909

References

  1. https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
  2. https://exim.org/static/doc/security/CVE-2026-40687.txt
  3. https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
  4. https://www.openwall.com/lists/oss-security/2026/04/30/21

1

TypeTargetConfidenceTier
WeaknessMissing Initialization of Resourcecwe-9090%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

CVE
CVE-2026-40685
CVE
CVE-2026-48840
CVE
CVE-2025-67896
CVE
CVE-2026-45185
CVE
Exim Out-of-bounds Write Vulnerability
CVE
Exim Buffer Overflow Vulnerability
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.