How severe is CVE-2020-8155?

CVE-2020-8155 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 user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-8155 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8155?

CVE-2020-8155 affects Nextcloud Nextcloud Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-8155?

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

When was CVE-2020-8155 published?

CVE-2020-8155 was published on 2020-05-12 and last updated on 2026-06-17.

CVE-2020-8155

CVE-2020-8155 is a medium-severity vulnerability in Nextcloud Nextcloud Server 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (63rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Nextcloud Nextcloud Server
Published: 2020-05-12
Last modified: 2026-06-17

Description

An outdated 3rd party library in the Files PDF viewer for Nextcloud Server 18.0.2 caused a Cross-site scripting vulnerability when opening a malicious PDF.

Frequently asked questions

What is CVE-2020-8155?: An outdated 3rd party library in the Files PDF viewer for Nextcloud Server 18.0.2 caused a Cross-site scripting vulnerability when opening a malicious PDF.
How severe is CVE-2020-8155?: CVE-2020-8155 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 user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-8155 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8155?: CVE-2020-8155 affects Nextcloud Nextcloud Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-8155?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-8155 published?: CVE-2020-8155 was published on 2020-05-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*

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