How severe is CVE-2018-20556?

CVE-2018-20556 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-20556 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 19% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20556?

CVE-2018-20556 affects Booking Calendar Project Booking Calendar. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-20556?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-20556 published?

CVE-2018-20556 was published on 2019-03-21 and last updated on 2026-06-17.

CVE-2018-20556

CVE-2018-20556 is a high-severity vulnerability in Booking Calendar Project Booking Calendar with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 19% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-89.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 19% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-89
Affected product: Booking Calendar Project Booking Calendar
Published: 2019-03-21
Last modified: 2026-06-17

Description

SQL injection vulnerability in Booking Calendar plugin 8.4.3 for WordPress allows remote attackers to execute arbitrary SQL commands via the booking_id parameter.

Frequently asked questions

What is CVE-2018-20556?: SQL injection vulnerability in Booking Calendar plugin 8.4.3 for WordPress allows remote attackers to execute arbitrary SQL commands via the booking_id parameter.
How severe is CVE-2018-20556?: CVE-2018-20556 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-20556 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 19% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20556?: CVE-2018-20556 affects Booking Calendar Project Booking Calendar. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-20556?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-20556 published?: CVE-2018-20556 was published on 2019-03-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:booking_calendar_project:booking_calendar:8.4.3:*:*:*:*:wordpress:*:*

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CVE-2017-2151 — Medium (CVSS 6.1): Cross-site scripting vulnerability in Booking Calendar version 7.1 and earlier allows remote attackers to inject…
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