Bug 2464248 (CVE-2026-40687)

Summary: CVE-2026-40687 Exim: Exim: Denial of Service and Information Disclosure via SPA authentication driver vulnerability
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Exim. When the Secure Password Authentication (SPA) driver processes input from a malicious SPA resource, it can lead to an out-of-bounds write, causing the connection to crash and resulting in a Denial of Service (DoS). This vulnerability also allows for the disclosure of sensitive data from uninitialized memory.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-04-30 22:01:30 UTC
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.