How severe is CVE-2020-8139?

CVE-2020-8139 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-8139 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8139?

CVE-2020-8139 primarily affects Nextcloud Nextcloud Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-8139?

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

When was CVE-2020-8139 published?

CVE-2020-8139 was published on 2020-03-20 and last updated on 2026-06-17.

CVE-2020-8139

CVE-2020-8139 is a medium-severity vulnerability in Nextcloud Nextcloud Server with a CVSS 3.x base score of 6.5. 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Nextcloud Nextcloud Server
Published: 2020-03-20
Last modified: 2026-06-17

Description

A missing access control check in Nextcloud Server < 18.0.1, < 17.0.4, and < 16.0.9 causes hide-download shares to be downloadable when appending /download to the URL.

Frequently asked questions

What is CVE-2020-8139?: A missing access control check in Nextcloud Server < 18.0.1, < 17.0.4, and < 16.0.9 causes hide-download shares to be downloadable when appending /download to the URL.
How severe is CVE-2020-8139?: CVE-2020-8139 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-8139 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8139?: CVE-2020-8139 primarily affects Nextcloud Nextcloud Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-8139?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-8139 published?: CVE-2020-8139 was published on 2020-03-20 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*

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