CVE-2021-24153 json
Yoast SEO < 3.4.1 - Authenticated Stored Cross-Site Scripting (XSS)
published 2021-04-05 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11067
- cvss
- 5.4
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 66%
- public exploits
- 0
- none known
Summary
A Stored Cross-Site Scripting vulnerability was discovered in the Yoast SEO WordPress plugin before 3.4.1, which had built-in blacklist filters which were blacklisting Parenthesis as well as several functions such as alert but bypasses were found.
Patch / fix
- yoast yoast_seo 3.4.1
Exploit prediction
1.11% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- packetstormsecurity.com https://packetstormsecurity.com/files/138192/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
Affected products
- Unknown Yoast SEO
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
-
packetstormsecurity.com
/files/138192/
exploit, third-party-advisory, vdb-entry
-
wpscan.com
/vulnerability/77810044-394d-4314-b9a1-20c7dca726dc
third-party-advisory
-
plugins.trac.wordpress.org
/changeset/1466243/wordpress-seo
third-party-advisory
Sources
- CVE List CVE-2021-24153
- NVD CVE-2021-24153
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