Security readout for executives and security teams
Plain-English summary
A flaw in the Fusion Builder WordPress plugin (versions up to and including 3.13.2) lets attackers slip malicious browser code into pages built with the plugin. If a logged-in user with editing rights is tricked into interacting with crafted content, the code runs in their browser and could hijack their session or alter what other site visitors see.
Executive priority
Schedule for the next routine maintenance cycle, not an emergency. The flaw is medium severity, requires an authenticated user and a click, and has no public exploitation. Treat as a planned WordPress hygiene task; escalate only if your site has many low-trust content contributors.
Technical view
CVE-2025-49940 is a DOM-based Cross-Site Scripting issue (CWE-79) in ThemeFusion's Fusion Builder plugin through 3.13.2. CVSS 3.1 6.5 (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L) indicates a network-reachable flaw needing low-privilege authentication and user interaction, with a scope change suggesting impact beyond the vulnerable component into the rendering browser context.
Likely exposure
Any WordPress site running Fusion Builder at or below 3.13.2 where contributors, authors, or editors can submit content. Sites that allow lower-privileged users to author or preview Fusion Builder elements have the broadest exposure surface; admin-only authoring sites are less exposed but not immune.
Exploitation context
No active exploitation is indicated; the CVE is not in CISA KEV and the cited Patchstack entry is a vulnerability database listing rather than an in-the-wild report. Exploitation requires an authenticated low-privilege account plus user interaction, which limits opportunistic mass attacks but remains realistic for multi-author sites and targeted phishing of editors.
Researcher notes
DOM-based XSS with scope change implies the sink executes in a context affecting other components, consistent with builder-rendered front-end output. No fixed version, patch commit, or affected-version floor is named in the bundle, so dependency on Patchstack/ThemeFusion advisories is unavoidable. Affected metadata lists "0" with defaultStatus "unaffected," suggesting incomplete CNA versioning; verify against vendor changelog before declaring a system patched.
Mitigation direction
- Inventory all WordPress sites and confirm whether Fusion Builder is installed and at what version.
- Update Fusion Builder to a version above 3.13.2 once ThemeFusion publishes a fix, per vendor guidance.
- Tighten Fusion Builder authoring roles so only trusted users can create or edit builder content.
- Place a web application firewall in front of WordPress to filter suspicious script payloads in editor inputs.
- Enforce strong authentication and session controls for all WordPress contributors, authors, and editors.
- Monitor Patchstack and ThemeFusion advisories for the patched release and apply promptly.
Validation and detection
- List Fusion Builder plugin versions across the WordPress estate and flag any at 3.13.2 or earlier.
- Confirm patched version is installed by checking plugin metadata after the vendor releases an update.
- Review WordPress user roles to verify least-privilege assignment for content authoring.
- Audit recently edited posts and pages for unexpected script tags or inline event handlers.
- Check WAF and access logs for anomalous editor-side requests targeting Fusion Builder endpoints.
- Re-test affected templates in a staging site to confirm DOM XSS no longer reproduces after patching.
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-2025-49940 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.