High severity · published Jul 24, 2026
CVE-2026-66141
Exim before 4.99.5 allows .forward privilege escalation because force_command for a pipe transport is mishandled
7.8
CVSS
0.1%
EPSS
No
On KEV
Description
Exim before 4.99.5 allows .forward privilege escalation because force_command for a pipe transport is mishandled.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EX
Exim · Exim
4.82 before 4.99.5 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66141
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-66141
Mailing List
https://openwall.com/lists/oss-security/2026/07/22/9
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