CVE-2020-12648
Cross-site scripting vulnerability in TinyMCE
A cross-site scripting (XSS) vulnerability in TinyMCE 5.2.1 and earlier allows remote attackers to inject arbitrary web script when configured in classic editing mode.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
6.1
A cross-site scripting (XSS) vulnerability in TinyMCE 5.2.1 and earlier allows remote attackers to inject arbitrary web script when configured in classic editing mode.
- Record
CVE-2020-12648- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
A cross-site scripting (XSS) vulnerability in TinyMCE 5.2.1 and earlier allows remote attackers to inject arbitrary web script when configured in classic editing mode.
- Record
CVE-2020-12648- Updated
- 2026-11-02
EUVDEUVD-2020-0644 No score
A cross-site scripting (XSS) vulnerability in TinyMCE 5.2.1 and earlier allows remote attackers to inject arbitrary web script when configured in classic editing mode.
- Record
EUVD-2020-0644- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-vrv8-v4w8-f95h
6.1
Cross-site scripting vulnerability in TinyMCE
Impact
A cross-site scripting (XSS) vulnerability was discovered in the core parser. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor via the clipboard or APIs. This impacts all users who are using TinyMCE 4.9.10 or lower and TinyMCE 5.4.0 or lower.
Patches
This vulnerability has been patched in TinyMCE 4.9.11 and 5.4.1 by improved HTML parsing and sanitization logic.
Workarounds
The workarounds available are:
- upgrade to either TinyMCE 4.9.11 or TinyMCE 5.4.1 or
- enable the media plugin, which overrides the default parsing behaviour for iframes or
- add the following workaround to update the parsing schema rules for iframes:
Example: Change the default schema for iframes
setup: function(editor) {
editor.on('PreInit', function() {
editor.schema.getSpecialElements()['iframe'] = /</iframe[^>]*>/gi;
});
}
Acknowledgements
Tiny Technologies would like to thank George Steketee and Chris Davis at Bishop Fox for discovering this vulnerability.
References
https://www.tiny.cloud/docs/release-notes/release-notes54/#securityfixes
For more information
If you have any questions or comments about this advisory:
- Open an issue in the TinyMCE repo
- Email us at [email protected]
- Record
GHSA-vrv8-v4w8-f95h- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
6.1
A cross-site scripting (XSS) vulnerability in TinyMCE 5.2.1 and earlier allows remote attackers to inject arbitrary web script when configured in classic editing mode.
- Record
CVE-2020-12648- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-vrv8-v4w8-f95h
6.1
Cross-site scripting vulnerability in TinyMCE
Impact
A cross-site scripting (XSS) vulnerability was discovered in the core parser. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor via the clipboard or APIs. This impacts all users who are using TinyMCE 4.9.10 or lower and TinyMCE 5.4.0 or lower.
Patches
This vulnerability has been patched in TinyMCE 4.9.11 and 5.4.1 by improved HTML parsing and sanitization logic.
Workarounds
The workarounds available are:
- upgrade to either TinyMCE 4.9.11 or TinyMCE 5.4.1 or
- enable the media plugin, which overrides the default parsing behaviour for iframes or
- add the following workaround to update the parsing schema rules for iframes:
Example: Change the default schema for iframes
setup: function(editor) {
editor.on('PreInit', function() {
editor.schema.getSpecialElements()['iframe'] = /</iframe[^>]*>/gi;
});
}
Acknowledgements
Tiny Technologies would like to thank George Steketee and Chris Davis at Bishop Fox for discovering this vulnerability.
References
https://www.tiny.cloud/docs/release-notes/release-notes54/#securityfixes
For more information
If you have any questions or comments about this advisory:
- Open an issue in the TinyMCE repo
- Email us at [email protected]
- Record
GHSA-vrv8-v4w8-f95h- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-12648
6.1
A cross-site scripting (XSS) vulnerability in TinyMCE 5.2.1 and earlier allows remote attackers to inject arbitrary web script when configured in classic editing mode.
- Record
UBUNTU-CVE-2020-12648- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
tinymcenpm |
before 4.9.11 | 4.9.11 |
tinymcenpm |
5.0.0 up to 5.4.1 | 5.4.1 |
tinymceUbuntu:16.04:LTS |
All versions, plus listed versions 3.4.8+dfsg0-1 |
None known |
tinymceUbuntu:18.04:LTS |
All versions, plus listed versions 3.4.8+dfsg0-2 |
None known |
tinymceUbuntu:20.04:LTS |
All versions, plus listed versions 3.4.8+dfsg0-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-12648 is a medium vulnerability (CVSS 6.1) in Tiny Tinymce, published August 11, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.80%, the 78th percentile. Fixed in tinymce 4.9.11.
References
labs.bishopfox.com/advisories/tinymce-version-5.2.1
github.com/tinymce/tinymce/security/advisories/GHSA-vrv8-v4w8-f95h
github.com/tinymce/tinymce/pull/5843
github.com/tinymce/tinymce/commit/2b71c922214d388838d930806207a66c14e80f63
github.com/tinymce/tinymce/commit/696e43658dc9750ec24fdc4650bd2be9653daf5b
tiny.cloud/docs/release-notes/release-notes54