CVE-2026-40687

4.8 MEDIUM 0.4% exploit odds Fix listed Memory safety OS & kernel

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in. Limited direct impact.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-04-30 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 10:45 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.4% in the next 30 days (EPSS).
Severity: 4.8 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-04-30 22:16 UTC
Last modified: 2026-06-17 10:45 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-909
Record status: Analyzed

Affected

Exim < 4.99.2

Attack profile CVSS 3.1 · 4.8

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: Low

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-40687.md and follow it. Check whether this project is affected by CVE-2026-40687. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record