CVE-2026-40685
6.5
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Summary
In Exim before 4.99.2, when JSON lookup is enabled, an out-of-bounds heap write can occur when a JSON operator encounters malformed JSON in an untrusted header, because of an incorrect implementation of \ skipping.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Exim | Exim | 0 < 4.99.2 | affected |
Weaknesses
- CWE-684: CWE-684 Incorrect Provision of Specified Functionality
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: partial
References
- https://www.openwall.com/lists/oss-security/2026/04/30/21
- https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40685.assessment
- https://code.exim.org/exim/exim/commit/9fdc057e71b87c87a0d3d2288b2810a0efaaba57
- https://exim.org/static/doc/security/CVE-2026-40685.txt
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