How severe is CVE-2018-8927?

CVE-2018-8927 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2018-8927 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-8927?

CVE-2018-8927 affects Synology Calendar. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-8927?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-8927 published?

CVE-2018-8927 was published on 2018-06-14 and last updated on 2026-06-17.

CVE-2018-8927

CVE-2018-8927 is a medium-severity vulnerability in Synology Calendar with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 4.0
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Synology Calendar
Published: 2018-06-14
Last modified: 2026-06-17

Description

Improper authorization vulnerability in SYNO.Cal.Event in Calendar before 2.1.2-0511 allows remote authenticated users to create arbitrary events via the (1) cal_id or (2) original_cal_id parameter.

Frequently asked questions

What is CVE-2018-8927?: Improper authorization vulnerability in SYNO.Cal.Event in Calendar before 2.1.2-0511 allows remote authenticated users to create arbitrary events via the (1) cal_id or (2) original_cal_id parameter.
How severe is CVE-2018-8927?: CVE-2018-8927 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2018-8927 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-8927?: CVE-2018-8927 affects Synology Calendar. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-8927?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-8927 published?: CVE-2018-8927 was published on 2018-06-14 and last updated on 2026-06-17.

References

https://www.synology.com/en-global/support/security/Synology_SA_18_16

Affected products (1)

cpe:2.3:a:synology:calendar:*:*:*:*:*:*:*:*

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