← Vulnerability feed

Vulnerability record · CVE-2020-12619 · published 20 August 2020

CVE-2020-12619: Freron mailmate vulnerability

Freron · Mailmate

MailMate before 1.11 automatically imported S/MIME certificates and thereby silently replaced existing ones. This allowed a man-in-the-middle attacker to obtain an email-validated S/MIME certificate from a trusted CA and replace the public key of the entity to be impersonated. This enabled the attacker to decipher further communication. The entire attack could be accomplished by sending a single email.

5.9 CVSS 3.1 Medium EPSS 0.43% · top 65.4%
5.9CVSS 3.1 base score, v2 4.3
0.43%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

MailMate before 1.11 automatically imported S/MIME certificates and thereby silently replaced existing ones. This allowed a man-in-the-middle attacker to obtain an email-validated S/MIME certificate from a trusted CA and replace the public key of the entity to be impersonated. This enabled the attacker to decipher further communication. The entire attack could be accomplished by sending a single email.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://updates.mailmate-app.com/2.0/release_notes Release NotesVendor Advisory
https://www.nds.ruhr-uni-bochum.de/media/nds/veroeffentlichungen/2020/08/15/mailto-paper.pdf Third Party Advisory
https://updates.mailmate-app.com/2.0/release_notes Release NotesVendor Advisory
https://www.nds.ruhr-uni-bochum.de/media/nds/veroeffentlichungen/2020/08/15/mailto-paper.pdf Third Party Advisory

Track CVE-2020-12619 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.5CVE-2018-15588Freron mailmate authentication bypass by spoofing vulnerabilityMailMate before 1.11.3 mishandles a suspicious HTML/MIME structure in a signed/encrypted email.EPSS 2.4%5.9CVE-2017-17688Apple mail vulnerabilityThe OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAI…EPSS 5.5%5.9CVE-2017-176899folders nine vulnerabilityThe S/MIME specification allows a Cipher Block Chaining (CBC) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAI…EPSS 4.1%

Source: NIST National Vulnerability Database (record CVE-2020-12619), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.