CVE-2026-40687: In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-

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.