Security readout for executives and security teams
Plain-English summary
CVE-2026-1300 is a stored cross-site scripting issue in the WordPress Responsive Header plugin through version 1.0. It requires an authenticated administrator-level user, limiting likely abuse. If triggered, injected scripts can run for users who view affected pages. This is most relevant to WordPress multisite or environments where unfiltered_html is disabled.
Executive priority
Treat as moderate priority. The vulnerability has limited reach because administrator access is required, but compromised admin accounts could turn it into a user-facing script injection issue. Address during routine WordPress plugin risk review, faster for multisite environments.
Technical view
The plugin insufficiently sanitizes and escapes multiple settings parameters, allowing administrator-level stored XSS. CVSS is 4.4, network exploitable, high privileges required, high attack complexity, changed scope, low confidentiality and integrity impact, and no availability impact. The source notes this only affects multisite installations and installations where unfiltered_html has been disabled.
Likely exposure
Exposure is limited to WordPress sites running Responsive Header version 1.0 or earlier, especially multisite deployments or sites with unfiltered_html disabled. An attacker needs administrator-level access, so this is mainly a defense-in-depth and insider or account-compromise concern.
Exploitation context
The provided sources do not indicate active exploitation, and the CVE is not listed as KEV. Exploitation requires access to plugin settings as an administrator or higher, then user exposure occurs when affected pages are viewed. No public exploit status is established in the provided bundle.
Researcher notes
Evidence identifies CWE-79 in plugin settings handling, with references to rhp-settings.php around line 103 in trunk and tag 1.0. The bundle does not name a fixed version or patch. Avoid assuming broader impact beyond Responsive Header through version 1.0 and the stated WordPress configuration conditions.
Mitigation direction
- Inventory WordPress sites for the Responsive Header plugin and installed version.
- Prioritize multisite installations and sites where unfiltered_html is disabled.
- Check the WordPress plugin page and vendor guidance for updates or remediation.
- Disable or remove the plugin if it is not business-critical.
- Limit administrator access and review accounts with plugin settings permissions.
Validation and detection
- Confirm whether Responsive Header is installed and at version 1.0 or earlier.
- Determine whether the site is WordPress multisite or has unfiltered_html disabled.
- Review plugin settings for unexpected script-like content or unauthorized changes.
- Check Wordfence and WordPress plugin pages for updated status or fixed versions.
- Monitor administrator account activity for suspicious settings changes.
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-2026-1300 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
- 4.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N
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:H/PR:H/UI:N/S:C/C:L/I:L/A:N1.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.4MediumVector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/30821418-48c0-4bc6-8bf1-f558671bff24?source=cveCVE reference
- https://downloads.wordpress.org/plugin/responsive-header.1.0.zipCVE reference
- https://wordpress.org/plugins/responsive-header/CVE reference
- https://plugins.trac.wordpress.org/browser/responsive-header/trunk/rhp-settings.php#L103CVE reference
- https://plugins.trac.wordpress.org/browser/responsive-header/tags/1.0/rhp-settings.php#L103CVE reference
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.