The WP Hotel Booking plugin for WordPress is vulnerable to Insufficient Verification of Data Authenticity in all versions up to, and including, 2.3.1. This is due to the web_hook_process_paypal_standard() IPN handler selecting its PayPal validation endpoint from the attacker-controlled $_REQUEST['test_ipn'] parameter, force-upgrading any pending transaction to completed when test_ipn=1, and omitting post-verification checks on receiver_email, mc_currency, and txn_id uniqueness after receiving a VERIFIED response from PayPal. This makes it possible for unauthenticated attackers to mark arbitrary hotel bookings as fully paid without submitting genuine payment to the merchant — either by routing IPN validation through PayPal's sandbox using a free sandbox account, or by replaying a previously verified IPN from a nominal payment to an attacker-controlled PayPal account. An attacker requires only a free PayPal sandbox account (or any PayPal account) to obtain a VERIFIED response; no site credentials or special configuration are needed.
CVE-2026-11901
MEDIUMPre-NVD 5.35.3—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 5.3 from GitHub Security Advisory published 2026-07-11. a secondary CVSS source baseline 5.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(high)
- EPSS
- 7.7%
- KEV
- Not listed
Published
July 11, 2026
Last Modified
July 11, 2026
References (10)
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L173
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L186
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L194
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.0/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L253
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L173
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L186
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L194
- security@wordfencehttps://plugins.trac.wordpress.org/browser/wp-hotel-booking/tags/2.3.1/includes/gateways/paypal/class-wphb-payment-gateway-paypal.php#L253
- security@wordfencehttps://plugins.trac.wordpress.org/changeset?reponame=&old=3582839%40wp-hotel-booking&new=3582839%40wp-hotel-booking
- security@wordfencehttps://www.wordfence.com/threat-intel/vulnerabilities/id/191ec7ea-6ca7-4943-8709-f372ae5a81c7?source=cve
Vendor Advisories for CVE-2026-11901(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-12 05:30 UTCEG score recompute
- 2026-07-12 05:30 UTCGHSA enrichment
- 2026-07-11 06:24 UTCEG score recompute
- 2026-07-11 06:22 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-345
Frequently asked(5)
What is CVE-2026-11901?
CVE-2026-11901 is a medium vulnerability published on July 11, 2026. The WP Hotel Booking plugin for WordPress is vulnerable to Insufficient Verification of Data Authenticity in all versions up to, and including, 2.3.1. This is due to the webhookprocesspaypalstandard() IPN handler selecting its PayPal validation endpoint from the attacker-controlled…
When was CVE-2026-11901 disclosed?
CVE-2026-11901 was first published in the National Vulnerability Database on July 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11901 actively exploited?
CVE-2026-11901 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 7.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-11901?
CVE-2026-11901 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-11901?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11901, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-11901
Is Your Infrastructure Affected by CVE-2026-11901?
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