CVE-2024-23184: Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive
Source GCVE Database
Not known to be exploited · CVSS 5.0 Medium.
Data as of 3 Nov 2026, 17:14 UTC
Thin evidence
One scorer or none| CNA (OX) | CVSS 3.1 | 5.0 |
|---|
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Sep 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
Description
Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive. With 100k header lines CPU usage is already 12 seconds, and in a production environment we observed 500k header lines taking 18 minutes to parse. Since this can be triggered by external actors sending emails to a victim, this is a security issue. An external attacker can send specially crafted messages that consume target system resources and cause outage. One can implement restrictions on address headers on MTA component preceding Dovecot. No publicly available exploits are known.
References
- nvd.nist.gov/vuln/detail/CVE-2024-23184 (opens in a new tab)
- documentation.open-xchange.com/dovecot/security/advisories/csaf/2024/oxdc-adv-2024-0002.json (opens in a new tab)
- lists.debian.org/debian-lts-announce/2024/09/msg00002.html (opens in a new tab)
- seclists.org/fulldisclosure/2024/Aug/17 (opens in a new tab)
- openwall.com/lists/oss-security/2024/08/15/3 (opens in a new tab)