Synced 16 Jun 2026 15:24 UTC Account
← All products

CVE-2020-36326

CRITICAL severity · CVSS 9.8 · Insecure deserialization
9.8CVSS CRITICAL

Summary

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.

Impact & exploitability

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)3%

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

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://github.com/PHPMailer/PHPMailer/commit/e2e07a355ee8ff36aba21d0242c5950c56e4c6f9 ↗