Critical severity · published Dec 14, 2025
CVE-2025-67896
Exim before 4.99.1, with certain non-default rate-limit configurations, allows a remote heap-based buffer overflow because database records are cast directly to internal…
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
Exim before 4.99.1, with certain non-default rate-limit configurations, allows a remote heap-based buffer overflow because database records are cast directly to internal structures without validation.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EX
Exim · Exim
before 4.99.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-67896
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-67896
Vendor Advisory
https://exim.org/static/doc/security/
Vendor Advisory
https://exim.org/static/doc/security/EXIM-Security-2025-12-09.1/report.txt
Mailing List
https://www.openwall.com/lists/oss-security/2025/12/11/2
Mailing List
http://www.openwall.com/lists/oss-security/2025/12/14/1
Mailing List
http://www.openwall.com/lists/oss-security/2025/12/18/3
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