# CVE-2026-40687

> Vulnerability · severity: **MEDIUM** (CVSS 4.8).

## 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.

## Key facts

- **CVE ID:** CVE-2026-40687
- **Published:** 2026-04-30
- **CVSS severity:** MEDIUM
- **CVSS base score:** 4.8
- **CWE codes:** CWE-909

## Affected products

- `exim:exim`

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40687

## Citation

> AI Analytics. CVE-2026-40687. Retrieved 2026-08-03 from https://api.ai-analytics.org/cve/CVE-2026-40687. Derived from NIST NVD. Licensed CC0.

---

*[Dataset catalog](https://api.ai-analytics.org/datasets/) · [AI Analytics](https://api.ai-analytics.org/) · CC0 1.0*