CVE-2026-40685

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.

Scoring

Severity
MEDIUM
CVSS base score
6.5
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
EPSS probability
0.32%
CWE
CWE-684
Published
2026-04-30
Last modified
2026-05-01

Affected products

Weakness type

Related vulnerabilities

Markdown version · Browse all CVEs