CVE-2026-3907 prasunsen CVE debrief

Who should care

Authenticated attackers with Contributor-level access and above can inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. WordPress users and administrators should review and update the Hostel plugin to prevent exploitation.

Technical summary

The Hostel plugin for WordPress has a Stored Cross-Site Scripting vulnerability via the 'wphostel-book' shortcode. The vulnerability exists due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. An authenticated attacker with Contributor-level access can inject malicious scripts, which will be executed when a user accesses the injected page. The vulnerability is caused by the second shortcode attribute being passed to the `$text` variable without sanitization at line 79 and then output directly into an HTML `value` attribute at line 91 without `esc_attr()` or any other escaping. This vulnerability can be exploited by authenticated attackers with Contributor-level access and above.

Defensive priority

Medium priority due to the CVSS score of 6.4 and the potential for authenticated attackers to inject arbitrary web scripts.

Recommended defensive actions

• Update the Hostel plugin to a version that includes a fix for this vulnerability.
• Restrict access to the WordPress dashboard to trusted users only.
• Implement a Web Application Firewall (WAF) to detect and prevent common web attacks.
• Regularly monitor WordPress sites for suspicious activity and update plugins promptly.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record was published on 2026-07-10T09:16:53.677Z and was last modified on 2026-07-10T15:43:30.330Z. The vulnerability was reported by [email protected]. Evidence is limited to CVE and NVD details. Defenders should verify the Hostel plugin version and review code for 'wphostel-book' shortcode usage.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.