CVE-2021-36855: Cross-Site Scripting (XSS) via Cross-Site Request Forgery (CSRF) vulnerability in Booking Ultra Pro plugin <=

Q: How do I fix CVE-2021-36855?

booking ultra pro appointments booking calendar: upgrade to newer than 1.1.4. Exact commands for each OS are on this page.

Q: Is CVE-2021-36855 being exploited?

CVE-2021-36855 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-36855 affect?

CVE-2021-36855 affects booking ultra pro appointments booking calendar. Severity is medium (CVSS 6.1). Cross-Site Scripting (XSS) via Cross-Site Request Forgery (CSRF) vulnerability in Booking Ultra Pro plugin <= 1.1.4 at WordPress.

Q: How urgent is CVE-2021-36855?

Priority 26/100. No elevated risk signals yet.

Routine

MEDIUM 6.1UPGRADE

CVE-2021-36855 is a medium-severity flaw (CVSS 6.1) affecting booking ultra pro appointments booking calendar. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross-Site Scripting (XSS) via Cross-Site Request Forgery (CSRF) vulnerability in Booking Ultra Pro plugin <= 1.1.4 at WordPress.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 80%)
CISA exploited list	No
Weakness	CWE-79, CWE-352
Published	2022-09-30
Last modified	2026-06-17

Publisher (CNA): Patchstack · Vendor: bookingultrapro

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-09-30 17:15 UTCPublished CVE record published
2026-06-17 03:59 UTCUpdated Record last modified

bookingultrapro booking ultra pro appointments booking calendar UPGRADE

Affected: <= 1.1.4

Fixed in: newer than 1.1.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy booking-ultra-pro-appointments-booking-calendar || rpm -q booking-ultra-pro-appointments-booking-calendar || booking-ultra-pro-appointments-booking-calendar --version

2. UPGRADE to newer than 1.1.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade booking-ultra-pro-appointments-booking-calendar

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade booking-ultra-pro-appointments-booking-calendar

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-36855?

booking ultra pro appointments booking calendar: upgrade to newer than 1.1.4. Exact commands for each OS are on this page.

Is CVE-2021-36855 being exploited?

CVE-2021-36855 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-36855 affect?

CVE-2021-36855 affects booking ultra pro appointments booking calendar. Severity is medium (CVSS 6.1). Cross-Site Scripting (XSS) via Cross-Site Request Forgery (CSRF) vulnerability in Booking Ultra Pro plugin <= 1.1.4 at WordPress.

How urgent is CVE-2021-36855?

Priority 26/100. No elevated risk signals yet.

Software pages

WordPress vulnerabilities

Related CVEs

CVE-2023-32511 HIGH 7.1 UPGRADE Unauth
CVE-2022-46816 MEDIUM 4.3 UPGRADE Cross-Site Request Forgery (CSRF) vulnerability in Booking Ultra Pro Appointments Booking Calendar Plugin plug
CVE-2021-36854 MEDIUM 5.4 UPGRADE Multiple Cross-Site Request Forgery (CSRF) vulnerabilities in Booking Ultra Pro plugin <= 1.1.4 at WordPress.

References

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