CVE-2026-3427 | Yoast SEO Plugin up to 27.1.1 on WordPress Block Attribute cross site scripting

VDB-352389 · CVE-2026-3427 · GCVE-0-2026-3427 YOAST SEO PLUGIN UP TO 27.1.1 ON WORDPRESS BLOCK ATTRIBUTE CROSS SITE SCRIPTING HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.9 $0-$5k 3.03 Summaryinfo A vulnerability identified as problematic has been detected in Yoast SEO Plugin up to 27.1.1 on WordPress. This issue affects some unknown processing of the component Block Attribute Handler. Performing a manipulation results in cross site scripting. This vulnerability is cataloged as CVE-2026-3427. It is possible to initiate the attack remotely. There is no exploit available. Detailsinfo A vulnerability, which was classified as problematic, was found in Yoast SEO Plugin up to 27.1.1 on WordPress. This affects some unknown functionality of the component Block Attribute Handler. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is: The Yoast SEO – Advanced SEO with real-time guidance and built-in AI plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the the `jsonText` block attribute in all versions up to, and including, 27.1.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The weakness was shared by Osvaldo Noe Gonzalez Del Rio. The advisory is shared at wordfence.com. This vulnerability is uniquely identified as CVE-2026-3427 since 03/02/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue. There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product. Productinfo Type WordPress Plugin Vendor Yoast Name SEO Plugin Version 27.1.0 27.1.1 CPE 2.3info 🔒 🔒 CPE 2.2info 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 4.9 VulDB Meta Temp Score: 4.9 VulDB Base Score: 3.5 VulDB Temp Score: 3.4 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 6.4 CNA Vector (Wordfence): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Cross site scripting CWE: CWE-79 / CWE-94 / CWE-74 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: no mitigation known Status: 🔍 0-Day Time: 🔒 Timelineinfo 03/02/2026 CVE reserved 03/22/2026 +20 days Advisory disclosed 03/22/2026 +0 days VulDB entry created 03/22/2026 +0 days VulDB entry last update Sourcesinfo Advisory: wordfence.com Researcher: Osvaldo Noe Gonzalez Del Rio Status: Not defined CVE: CVE-2026-3427 (🔒) GCVE (CVE): GCVE-0-2026-3427 GCVE (VulDB): GCVE-100-352389 Entryinfo Created: 03/22/2026 05:14 Changes: 03/22/2026 05:14 (65) Complete: 🔍 Cache ID: 99:8E8:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸