CVE-2021-23342
Cross-site Scripting (XSS)
This affects the package docsify before 4.12.0. It is possible to bypass the remediation done by CVE-2020-7680 and execute malicious JavaScript through the following methods 1) When parsing HTML from remote URLs, the HTML code on the main page is sanitized, but this sanitization is not taking place in the sidebar. 2) The isURL external check can be bypassed by inserting more “////” characters
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Cross-site Scripting (XSS)
This affects the package docsify before 4.12.0. It is possible to bypass the remediation done by CVE-2020-7680 and execute malicious JavaScript through the following methods 1) When parsing HTML from remote URLs, the HTML code on the main page is sanitized, but this sanitization is not taking place in the sidebar. 2) The isURL external check can be bypassed by inserting more “////” characters
- Record
CVE-2021-23342- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L/E:P/RL:U/RC:C - Updated
- 2026-11-02
EUVDEUVD-2021-0585
This affects the package docsify before 4.12.0. It is possible to bypass the remediation done by CVE-2020-7680 and execute malicious JavaScript through the following methods 1) When parsing HTML from remote URLs, the HTML code on the main page is sanitized, but this sanitization is not taking place in the sidebar. 2) The isURL external check can be bypassed by inserting more “////” characters
- Record
EUVD-2021-0585- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L/E:P/RL:U/RC:C - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-2mm9-c2fx-c7m4
Docsify XSS Vulnerability
This affects the package docsify before 4.12.0. It is possible to bypass the remediation done by CVE-2020-7680 and execute malicious JavaScript through the following methods 1) When parsing HTML from remote URLs, the HTML code on the main page is sanitized, but this sanitization is not taking place in the sidebar. 2) The isURL external check can be bypassed by inserting more //// characters
- Record
GHSA-2mm9-c2fx-c7m4- 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
NVD
This affects the package docsify before 4.12.0. It is possible to bypass the remediation done by CVE-2020-7680 and execute malicious JavaScript through the following methods 1) When parsing HTML from remote URLs, the HTML code on the main page is sanitized, but this sanitization is not taking place in the sidebar. 2) The isURL external check can be bypassed by inserting more “////” characters
- Record
CVE-2021-23342- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L - 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
OSV
This affects the package docsify before 4.12.0. It is possible to bypass the remediation done by CVE-2020-7680 and execute malicious JavaScript through the following methods 1) When parsing HTML from remote URLs, the HTML code on the main page is sanitized, but this sanitization is not taking place in the sidebar. 2) The isURL external check can be bypassed by inserting more “////” characters
- Record
CVE-2021-23342- 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-2mm9-c2fx-c7m4
Docsify XSS Vulnerability
This affects the package docsify before 4.12.0. It is possible to bypass the remediation done by CVE-2020-7680 and execute malicious JavaScript through the following methods 1) When parsing HTML from remote URLs, the HTML code on the main page is sanitized, but this sanitization is not taking place in the sidebar. 2) The isURL external check can be bypassed by inserting more //// characters
- Record
GHSA-2mm9-c2fx-c7m4- 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
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
docsifynpm |
before 4.12.0 | 4.12.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-23342 is a high vulnerability (CVSS 8.6) in Docsifyjs Docsify, published February 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.66%, the 76th percentile. Fixed in docsify 4.12.0.
References
snyk.io/vuln/SNYK-JS-DOCSIFY-1066017
github.com/docsifyjs/docsify/commit/ff2a66f12752471277fe81a64ad6c4b2c08111fe
seclists.org/fulldisclosure/2021/Feb/71
packetstormsecurity.com/files/161495/docsify-4.11.6-Cross-Site-Scripting.html
nvd.nist.gov/vuln/detail/CVE-2021-23342
npmjs.com/package/docsify