5.4

CVE-2021-24153: Yoast SEO < 3.4.1 - Authenticated Stored Cross-Site Scripting (XSS)

Modified
Published 05-04-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-24153 is a medium (CVSS 5.4) Cross-site Scripting vulnerability in unknown yoast seo. EPSS estimates a 1.11% chance of exploitation in the next 30 days, higher than 65.7% of scored vulnerabilities. 1 public exploit is recorded. Fixed in 3.4.1.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
5.4/10
010
Medium · v3.1 (NVD)
EPSS score
1.11%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Timeline

  1. 05-04-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.11%

Chance of exploitation in the next 30 days

Percentile

66%

Versus all other CVEs

30-day change

No change 0.00 pp

From 1.11% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (packetstormsecurity.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Unknown1 product
Wordpress1 product
  • wordpress-seo< 3.4.1
Yoast1 product

3 vendors · 3 products

References

4 links