CVE-2021-24591
Highlight < 0.9.3 - Authenticated Stored Cross-Site Scripting
The Highlight WordPress plugin before 0.9.3 does not sanitise its CustomCSS setting, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
The Highlight WordPress plugin before 0.9.3 does not sanitise its CustomCSS setting, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed
- Record
CVE-2021-24591- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
Highlight < 0.9.3 - Authenticated Stored Cross-Site Scripting
The Highlight WordPress plugin before 0.9.3 does not sanitise its CustomCSS setting, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed
- Record
CVE-2021-24591- Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-11503 No score
The Highlight WordPress plugin before 0.9.3 does not sanitise its CustomCSS setting, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed
- Record
EUVD-2021-11503- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-c3m7-gw6j-3wx2 No score
The Highlight WordPress plugin before 0.9.3 does not sanitise its CustomCSS setting, allowing...
The Highlight WordPress plugin before 0.9.3 does not sanitise its CustomCSS setting, allowing high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed
- Record
GHSA-c3m7-gw6j-3wx2- Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-24591 is a medium vulnerability (CVSS 5.4) in Dn88 Highlight, published September 6, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 50th percentile. No source names a fixed version.