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Not in CISA KEV
MEDIUM severity

CVE-2021-31779 — yoast_seo

MEDIUM

CVE-2021-31779 is a medium-severity (CVSS 6.4) Server-Side Request Forgery (SSRF) vulnerability in yoast-seo-for-typo3/yoast_seo. A fix is available for yoast-seo-for-typo3/yoast_seo — see the affected versions and patch details below.

Server-Side Request Forgery in yoast_seo

Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk
0.00%0.32%0.65%0.97%0.1%0.5%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-31779 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected
🐘yoast-seo-for-typo3/yoast_seo

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

The yoast_seo (aka Yoast SEO) extension before 7.2.1 for TYPO3 allows SSRF via a backend user account.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistyoast-seo-for-typo3/yoast_seoall versions7.2.1composer require yoast-seo-for-typo3/yoast_seo:^7.2.1

Affected Products

1 product · 1 configurations
Application
yoast seoyoast
< 7.2.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yoast-seo-for-typo3/yoast_seo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update yoast-seo-for-typo3/yoast_seo to 7.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-31779 is resolved across your whole dependency graph.

  3. Workarounds

    Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

The yoast_seo (aka Yoast SEO) extension before 7.2.1 for TYPO3 allows SSRF via a backend user account.
O3 Security · Impact-Aware SCA

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CVE-2021-31779: yoast_seo SSRF — Fixed in 7.2.1