CVSS 6.5 · MEDIUM
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.
View on NVDSeverity
Score: 6.5(MEDIUM)
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:HAV: NETWORK
AC: HIGH
PR: NONE
UI: NONE
S: UNCHANGED
C: NONE
I: LOW
A: HIGH
Weakness (CWE):
CWE-684CWE-787EPSS
Probability of exploitation (next 30 days): 0.0007 (0.1%)
Percentile: 21.3%
EPSS: 2026-05-06
Affects
exim:eximTechnical description
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.
Published: 4/30/2026, 10:16:25 PM
Last modified: 5/1/2026, 5:51:06 PM