How severe is CVE-2019-12739?

CVE-2019-12739 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-12739 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-12739?

CVE-2019-12739 affects Nextcloud Extract. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-12739?

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

When was CVE-2019-12739 published?

CVE-2019-12739 was published on 2019-06-05 and last updated on 2026-06-17.

CVE-2019-12739

CVE-2019-12739 is a critical-severity vulnerability in Nextcloud Extract with a CVSS 3.x base score of 9.0. 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-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.0)
CVSS v2: 6.5
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Nextcloud Extract
Published: 2019-06-05
Last modified: 2026-06-17

Description

lib/Controller/ExtractionController.php in the Extract add-on before 1.2.0 for Nextcloud allows Remote Code Execution via shell metacharacters in a RAR filename via ajax/extractRar.php (nameOfFile and directory parameters).

Frequently asked questions

What is CVE-2019-12739?: lib/Controller/ExtractionController.php in the Extract add-on before 1.2.0 for Nextcloud allows Remote Code Execution via shell metacharacters in a RAR filename via ajax/extractRar.php (nameOfFile and directory parameters).
How severe is CVE-2019-12739?: CVE-2019-12739 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-12739 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-12739?: CVE-2019-12739 affects Nextcloud Extract. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-12739?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2019-12739 published?: CVE-2019-12739 was published on 2019-06-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:extract:*:*:*:*:*:nextcloud:*:*

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