Security readout for executives and security teams
Plain-English summary
CVE-2026-1821 affects the Microtango WordPress plugin. A logged-in user with Contributor-level access or higher can place malicious script in a reservation shortcode attribute. That script can run later when someone views the affected page. This is not reported as actively exploited in the provided sources.
Executive priority
Treat as a moderate website integrity and account-trust issue. Prioritize sites where many authors can post content, external contributors exist, or administrators view contributor-created pages. It is less urgent than unauthenticated remote compromise but should be remediated promptly.
Technical view
Microtango versions up to and including 0.9.29 are vulnerable to stored XSS in the restkey parameter of the mt_reservation shortcode. The issue is insufficient input sanitization and output escaping. CVSS 3.1 score is 6.4, CWE-79, requiring low-privileged authenticated access.
Likely exposure
Exposure is limited to WordPress sites running Microtango through 0.9.29, especially where Contributor or higher accounts can create or edit shortcode content. Sites without this plugin, without affected versions, or without untrusted authenticated authors have lower exposure.
Exploitation context
An attacker needs an authenticated WordPress account with Contributor-level privileges or higher. Successful abuse can execute script in browsers of users who visit the injected page, potentially affecting session data or page integrity. The source bundle does not show KEV listing or confirmed active exploitation.
Researcher notes
The public record identifies restkey in mt_reservation as the vulnerable shortcode attribute. WordPress Trac references include the vulnerable 0.9.29 file and a changeset, but the provided bundle does not clearly name a fixed release. Avoid assuming patch status beyond vendor guidance.
Mitigation direction
- Inventory WordPress sites for the Microtango plugin and installed version.
- Check WordPress plugin/vendor guidance for an updated fixed release.
- Restrict Contributor-level and higher access to trusted users only.
- Review and remove suspicious mt_reservation shortcode content.
- Temporarily disable the plugin if business risk outweighs availability needs.
Validation and detection
- Confirm whether Microtango is installed and at version 0.9.29 or earlier.
- Review pages and posts containing mt_reservation shortcodes.
- Audit recent content changes by Contributor-level or higher users.
- Check vendor references and WordPress Trac changes for remediation status.
- Monitor for unexpected script execution reports on affected pages.
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-2026-1821 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/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:L/PR:L/UI:N/S:C/C:L/I:L/A:N3.12.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/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/27657d29-e834-4f05-8fe9-7db0ab96f67d?source=cveCVE reference
- https://plugins.trac.wordpress.org/browser/microtango/trunk/microtango-init.php#L129CVE reference
- https://plugins.trac.wordpress.org/browser/microtango/tags/0.9.29/microtango-init.php#L129CVE reference
- https://plugins.trac.wordpress.org/changeset/3455880/CVE 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.