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Fencer Vulns
critical 9.8

CVE-2020-36326 in the critical feed json

Object injection in PHPMailer/PHPMailer

published 2021-04-28 5 y ago modified 2026-09-08 2 mo ago also BIT-phpmailer-2020-36326 , BIT-wordpress-2020-36326 , BIT-wordpress-multisite-2020-36326 , EUVD-2021-1129 , GHSA-m298-fh5c-jc66

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.1%
EPSS 3.1% chance of exploitation in 30 days, percentile 87%
public exploits
0
none known

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.

Patch / fix

  • packagist phpmailer/phpmailer 6.4.1
  • bitnami phpmailer 6.4.1
  • bitnami wordpress 3.7.36, 3.8.36, 3.9.34, 4.0.33, 4.1.33, 4.2.30, 4.3.26, 4.4.25, 4.5.24, 4.6.21, 4.7.21, 4.8.17, 4.9.18, 5.0.13, 5.1.10, 5.2.11, 5.3.8, 5.4.6, 5.5.5, 5.6.4, 5.7.2
  • bitnami wordpress-multisite 3.7.36, 3.8.36, 3.9.34, 4.0.33, 4.1.33, 4.2.30, 4.3.26, 4.4.25, 4.5.24, 4.6.21, 4.7.21, 4.8.17, 4.9.18, 5.0.13, 5.1.10, 5.2.11, 5.3.8, 5.4.6, 5.5.5, 5.6.4, 5.7.2
  • wordpress wordpress 3.7.36, 3.8.36, 3.9.34, 4.0.33, 4.1.33, 4.2.30, 4.3.26, 4.4.25, 4.5.24, 4.6.21, 4.7.21, 4.8.17, 4.9.18, 5.0.13, 5.1.10, 5.2.11, 5.3.8, 5.4.6, 5.5.5, 5.6.4
  • libphp-phpmailer Debian 14, Debian 13, Debian 12 6.2.0-2

debian advisories DEBIAN-CVE-2020-36326

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-36326 updated cvss 8.1

php-phpmailer6: Object injection through Phar Deserialization via addAttachment with a UNC pathname

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.09% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
OSV 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
packagist phpmailer/phpmailer
>=6.1.8, <6.4.1
6.4.1
bitnami phpmailer
>=6.1.8, <6.4.1
6.4.1
bitnami wordpress
>=3.7.0, <3.7.36
>=3.8.0, <3.8.36
>=3.9.0, <3.9.34
>=4.0.0, <4.0.33
>=4.1.0, <4.1.33
>=4.2.0, <4.2.30
>=4.3.0, <4.3.26
>=4.4.0, <4.4.25
>=4.5.0, <4.5.24
>=4.6.0, <4.6.21
>=4.7.0, <4.7.21
>=4.8.0, <4.8.17
>=4.9.0, <4.9.18
>=5.0.0, <5.0.13
>=5.1.0, <5.1.10
>=5.2.0, <5.2.11
>=5.3.0, <5.3.8
>=5.4.0, <5.4.6
>=5.5.0, <5.5.5
>=5.6.0, <5.6.4
>=5.7.0, <5.7.2
3.7.36
3.8.36
3.9.34
4.0.33
4.1.33
4.2.30
4.3.26
4.4.25
4.5.24
4.6.21
4.7.21
4.8.17
4.9.18
5.0.13
5.1.10
5.2.11
5.3.8
5.4.6
5.5.5
5.6.4
5.7.2
bitnami wordpress-multisite
>=3.7.0, <3.7.36
>=3.8.0, <3.8.36
>=3.9.0, <3.9.34
>=4.0.0, <4.0.33
>=4.1.0, <4.1.33
>=4.2.0, <4.2.30
>=4.3.0, <4.3.26
>=4.4.0, <4.4.25
>=4.5.0, <4.5.24
>=4.6.0, <4.6.21
>=4.7.0, <4.7.21
>=4.8.0, <4.8.17
>=4.9.0, <4.9.18
>=5.0.0, <5.0.13
>=5.1.0, <5.1.10
>=5.2.0, <5.2.11
>=5.3.0, <5.3.8
>=5.4.0, <5.4.6
>=5.5.0, <5.5.5
>=5.6.0, <5.6.4
>=5.7.0, <5.7.2
3.7.36
3.8.36
3.9.34
4.0.33
4.1.33
4.2.30
4.3.26
4.4.25
4.5.24
4.6.21
4.7.21
4.8.17
4.9.18
5.0.13
5.1.10
5.2.11
5.3.8
5.4.6
5.5.5
5.6.4
5.7.2

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data
  • CWE-641 Improper Restriction of Names for Files and Other Resources
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.