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-16325121
- published1 May 2026
- disclosed30 Apr 2026
- creditUnknown
Introduced: 30 Apr 2026
CVE-2026-40685 (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 in the JSON lookup process when malformed JSON is encountered in an untrusted header due to incorrect implementation of backslash skipping. An attacker can cause a heap out-of-bounds write by supplying specially crafted JSON data in email headers.