CVE-2019-17022: XSS
Last updated 25 August 2025
Other sources
When pasting a <style> tag from the clipboard into a rich text editor, the CSS sanitizer does not escape < and > characters. Because the resulting string is pasted directly into the text node of the element this does not result in a direct injection into the webpage; however, if a webpage subsequently copies the node's innerHTML, assigning it to another innerHTML, this would result in an XSS vulnerability. Two WYSIWYG editors were identified with this behavior, more may exist. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.
— Launchpad
When pasting a <style> tag from the clipboard into a rich text editor, the CSS sanitizer does not escape < and > characters. Because the resulting string is pasted directly into the text node of the element this does not result in a direct injection into the webpage; however, if a webpage subsequently copies the node's innerHTML, assigning it to another innerHTML, this would result in an XSS vulnerability. Two WYSIWYG editors were identified with this behavior, more may exist.
External Reference:
https://www.mozilla.org/en-US/security/advisories/mfsa2020-02/#CVE-2019-17022
— Red Hat
When pasting a <style> tag from the clipboard into a rich text editor, the CSS sanitizer does not escape < and > characters. Because the resulting string is pasted directly into the text node of the element this does not result in a direct injection into the webpage; however, if a webpage subsequently copies the node's innerHTML, assigning it to another innerHTML, this would result in an XSS vulnerability. Two WYSIWYG editors were identified with this behavior, more may exist.
— Mozilla
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/firefoxto a version that resolves this vulnerability.Fixed in 68.4 - Upgrade
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redhat/thunderbirdto a version that resolves this vulnerability.Fixed in 68.4.1 - Upgrade
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Thunderbirdto a version that resolves this vulnerability.Fixed in 68.4.1 - Upgrade
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Firefoxto a version that resolves this vulnerability.Fixed in 72 - Upgrade
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Firefox ESRto a version that resolves this vulnerability.Fixed in 68.4 - Upgrade
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debian/firefoxto a version that resolves this vulnerability.Fixed in 149.0.2-1 - Upgrade
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debian/firefox-esrto a version that resolves this vulnerability.Fixed in 115.14.0esr-1~deb11u1Fixed in 140.9.1esr-1~deb11u1Fixed in 128.14.0esr-1~deb12u1Fixed in 140.9.1esr-1~deb12u1Fixed in 140.8.0esr-1~deb13u1Fixed in 140.9.1esr-1~deb13u1Fixed in 140.9.1esr-1 - Upgrade
Upgrade
debian/thunderbirdto a version that resolves this vulnerability.Fixed in 1:115.12.0-1~deb11u1Fixed in 1:140.9.1esr-1~deb11u1Fixed in 1:140.6.0esr-1~deb12u1Fixed in 1:140.9.1esr-1~deb12u1Fixed in 1:140.8.0esr-1~deb13u1Fixed in 1:140.9.1esr-1~deb13u1Fixed in 1:140.9.0esr-1Fixed in 1:140.9.1esr-1 - Upgrade
Upgrade
alpine/firefoxto a version that resolves this vulnerability.Fixed in 71.0.1-r0 - Upgrade
Upgrade
alpine/firefox-esrto a version that resolves this vulnerability.Fixed in 68.4.1-r0 - Upgrade
Upgrade
alpine/librewolfto a version that resolves this vulnerability.Fixed in 71.0.1-r0
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is CVE-2019-17022?
CVE-2019-17022 is a vulnerability in Mozilla Firefox and Thunderbird that allows the execution of arbitrary CSS code.
How does CVE-2019-17022 affect Mozilla Firefox ESR?
CVE-2019-17022 affects Mozilla Firefox ESR version 68.4, allowing the execution of arbitrary CSS code when pasting a <style> tag from the clipboard into a rich text editor.
How does CVE-2019-17022 affect Mozilla Thunderbird?
CVE-2019-17022 affects Mozilla Thunderbird version 68.4.1, allowing the execution of arbitrary CSS code when pasting a <style> tag from the clipboard into a rich text editor.
How does CVE-2019-17022 affect Mozilla Firefox?
CVE-2019-17022 affects Mozilla Firefox version up to 72, allowing the execution of arbitrary CSS code when pasting a <style> tag from the clipboard into a rich text editor.
How severe is CVE-2019-17022?
CVE-2019-17022 has a severity rating of medium (4 out of 10).