Incorrect Provision of Specified Functionality Affecting exim/exim package, versions [,4.99.2)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-EXIMEXIM-16325122
- published1 May 2026
- disclosed30 Apr 2026
- creditUnknown
Introduced: 30 Apr 2026
CVE-2026-40684 (opens in a new tab)How to fix?
Upgrade exim/exim to version 4.99.2 or higher.
Overview
Affected versions of this package are vulnerable to Incorrect Provision of Specified Functionality when processing PTR records containing malformed DNS data via the dn_expand function. An attacker can cause the connection instance to crash by supplying specially crafted DNS responses. This is only exploitable if the system is built with musl libc rather than glibc.