Deserialization in Phpmailer Project
CVE-2020-36326
PHPMailer 6.1.8 through 6.4.0 allows object injection through Phar Deserialization via addAttachment with a UNC pathname. NOTE: this is similar to CVE-2018-19296, but arose because 6.1.8 fixed a functionality problem in which UNC pathnames were always considered unreadable by PHPMailer, even in safe contexts. As an unintended side effect, this fix eliminated the code that blocked addAttachment exploitation.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.031 (87.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 87.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.031 · newest: 0.031 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/PHPMailer/PHPMailer/commit/e2e07a355ee8ff36aba21d0242c5950c56e4c6f9 (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2020-36326?
- CVE-2020-36326 is a critical-severity vulnerability in Phpmailer Project, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2021-04-28.
- How severe is CVE-2020-36326?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2020-36326 known to be exploited?
- 6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.