Quick Event Manager 9.9.5 - 9.18 - Unauthenticated PayPal IPN Verification Bypass via the 'debug' Parameter
- Exploited
- No known exploitation
- Fix
- Fixed in 9.19
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 9.19.
- Last modified
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.11% · 1st percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 25/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
The Quick Event Manager WordPress plugin does not properly verify PayPal payment notifications before marking event registrations as paid. Remotely, without logging in, an attacker could mark registrations as paid without actually making a payment.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
The Quick Event Manager WordPress plugin before 9.19 does not verify the authenticity of PayPal payment notifications before marking event registrations as paid, which could allow unauthenticated attackers to mark registrations as paid without making a payment.
cve.now Index
- Exploitation0/40No signal
- Exposure20/25No login or user action needed per the CVSS vector, CISA rates it automatable · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity5.3/10CVSS 5.3
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 9.19.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- Unknown Quick Event Manager
From 9.9.5 · fixed in 9.19
Evidence 1
- Exploit
Corrections
None so far.
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Questions about CVE-2026-121636
Is CVE-2026-121636 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-121636?
Quick Event Manager: from 9.9.5 before 9.19.Source: cve.now feed data
How do I fix CVE-2026-121636?
Upgrade to a fixed version: 9.19.Source: cve.now feed data