CVE-2020-11026 [High] | XSS in Wordpress

In affected versions of WordPress, files with a specially crafted name when uploaded to the Media section can lead to script execution upon accessing the file. This requires an authenticated user with privileges to upload files. This has been patched in version 5.4.1, along with all the previously affected versions via a minor release (5.3.3, 5.2.6, 5.1.5, 5.0.9, 4.9.14, 4.8.13, 4.7.17, 4.6.18, 4.5.21, 4.4.22, 4.3.23, 4.2.27, 4.1.30, 4.0.30, 3.9.31, 3.8.33, 3.7.33).

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	4.41%	2.09%	-2.32%
2	2026-03-04	3.96%	4.41%	+0.45%
3	2026-03-01	—	3.96%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

4.41%

2.09%

-2.32%

2026-03-04

3.96%

4.41%

+0.45%

2026-03-01

—

3.96%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
8.7	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.	2.3	5.8	[email protected]
5.4	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.3	2.7	[email protected]
3.5	2.0	LOW	`AV:N/AC:M/Au:S/C:N/I:P/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	6.8	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

8.7

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N): Service keeps running; no real outage angle.

2.3

5.8

[email protected]

5.4

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.3

2.7

[email protected]

3.5

2.0

LOW

AV:N/AC:M/Au:S/C:N/I:P/A:N Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S): A single authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

6.8

2.9

[email protected]

OS Trackers for CVE-2020-11026

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2020-11026 not yet assigned priority: Debian including 1 source packages (wordpress), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2020-11026
`ubuntu`	medium	CVE-2020-11026 medium priority: Ubuntu including 1 source packages (wordpress), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 9, needed 6, DNE 1, released 1.	https://ubuntu.com/security/CVE-2020-11026

Affected software / configurations for CVE-2020-11026

Vendor	Product	Version	Raw CPE
wordpress	wordpress	>= 3.7, < 3.7.33	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 3.8, < 3.8.33	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 3.9, < 3.9.31	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.0, < 4.0.30	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.1, < 4.1.30	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.2, < 4.2.27	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.3, < 4.3.23	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.4, < 4.4.22	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.5, < 4.5.21	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.6, < 4.6.18	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.7, < 4.7.17	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.8, < 4.8.13	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 4.9, < 4.9.14	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 5.0, < 5.0.9	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 5.1, < 5.1.5	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 5.2, < 5.2.6	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	>= 5.3, < 5.3.3	cpe:2.3:a:wordpress:wordpress::::::::
wordpress	wordpress	5.4	cpe:2.3:a:wordpress:wordpress:5.4:::::::*
debian	debian_linux	8.0	cpe:2.3:o:debian:debian_linux:8.0:::::::*
debian	debian_linux	9.0	cpe:2.3:o:debian:debian_linux:9.0:::::::*
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*

References for CVE-2020-11026

URL	Tags
https://github.com/WordPress/wordpress-develop/security/advisories/GHSA-3gw2-4656-pfr2	Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/05/msg00011.html	Mailing List Third Party Advisory
https://wordpress.org/support/wordpress-version/version-5-4-1/#security-updates	Release Notes Vendor Advisory
https://www.debian.org/security/2020/dsa-4677	Third Party Advisory

URL

CVE-2020-11026 | Specially crafted filenames in WordPress leading to XSS

Exploit prediction scoring system (EPSS) score for CVE-2020-11026

Common vulnerability scoring system (CVSS) metrics for CVE-2020-11026

Weakness enumeration for CVE-2020-11026

OS Trackers for CVE-2020-11026

Affected software / configurations for CVE-2020-11026

References for CVE-2020-11026