Security readout for executives and security teams
Plain-English summary
A WordPress plugin called Ultimate Blocks (versions up to and including 3.3.6) has a stored cross-site scripting flaw. A contributor-level user could save malicious script content that later runs in another visitor's browser, potentially hijacking sessions or defacing pages. Sites using this plugin should review the vendor advisory and update when a fix is available.
Executive priority
Schedule remediation in the normal patch cycle for sites that grant write access to multiple users; treat as elevated priority for any site with external contributors. Risk is meaningful but not emergency-grade absent active exploitation evidence.
Technical view
CVE-2025-49929 is a stored XSS (CWE-79) in the Ultimate Blocks WordPress plugin through 3.3.6. CVSS 3.1 base 6.5 (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L) indicates network exploitation by an authenticated low-privilege user with victim interaction, with scope change across the rendered page context. Input is not properly neutralized during web page generation, enabling persistent script injection.
Likely exposure
Any WordPress site running Ultimate Blocks 3.3.6 or earlier that grants contributor, author, or editor accounts to multiple users is exposed. Public-facing marketing, blog, and CMS sites that allow guest authors or external collaborators are most at risk because low-privilege accounts can plant the payload.
Exploitation context
No public reports of in-the-wild exploitation and not listed in CISA KEV at time of writing. The Patchstack advisory is the primary disclosure source. The CVSS vector requires authenticated low-privilege access plus user interaction, lowering opportunistic mass-exploitation risk but not insider or compromised-account risk.
Researcher notes
Stored XSS with scope change (S:C) suggests payload execution can affect resources beyond the vulnerable component, consistent with admin-context impact when an administrator views injected content. PR:L plus UI:R indicates an authenticated contributor pathway. Patchstack lists the issue against versions through 3.3.6; a fixed version, root-cause sink, and exact attack vector are not detailed in the public CVE record reviewed.
Mitigation direction
- Inventory WordPress sites and identify any installation of the Ultimate Blocks plugin at version 3.3.6 or earlier.
- Check the Patchstack advisory and vendor plugin page for an updated release and apply it once published.
- Restrict contributor, author, and editor account creation; review existing low-privilege accounts for legitimacy.
- If no fix is available, deactivate the plugin or place the site behind a WAF with XSS filtering until patched.
- Enable a Content Security Policy that blocks inline scripts to reduce stored-XSS impact site-wide.
Validation and detection
- Run wp plugin list or inspect wp-content/plugins/ultimate-blocks to confirm presence and version.
- After updating, verify the plugin version reported in the WordPress admin matches the fixed release noted by the vendor.
- Review post and page content created by low-privilege accounts for suspicious script tags or event handlers.
- Audit site logs and security plugin alerts for unexpected admin sessions or content edits since plugin install.
- Run an authenticated and unauthenticated web vulnerability scan targeting blocks rendered by the plugin to confirm no payload reflects.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-49929 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L2.33.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.