High severity · published Sep 27, 2026
CVE-2026-100888
Trusted Domain Project OpenDKIM DKIM Signature Header Selection dkim-canon.c dkim_canon_selecthdrs out-of-bounds write
7.3
CVSS
0.3%
EPSS
No
On KEV
Description
A weakness has been identified in Trusted Domain Project OpenDKIM up to 2.11.0. This affects the function dkim_canon_selecthdrs of the file libopendkim/dkim-canon.c of the component DKIM Signature Header Selection. Executing a manipulation of the argument h can lead to out-of-bounds write. The attack can be executed remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenDKIM · Trusted Domain Project
2.0; 2.1; 2.2; 2.3; 2.4; 2.5; +6 more · source: vendor