How severe is CVE-2018-20834?

CVE-2018-20834 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2018-20834 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20834?

CVE-2018-20834 affects Isaacs Tar. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-20834?

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-2018-20834 published?

CVE-2018-20834 was published on 2019-04-30 and last updated on 2026-06-17.

CVE-2018-20834

CVE-2018-20834 is a high-severity vulnerability in Isaacs Tar with a CVSS 3.x base score of 7.5. 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-59.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 6.4
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-59
Affected product: Isaacs Tar
Published: 2019-04-30
Last modified: 2026-06-17

Description

A vulnerability was found in node-tar before version 4.4.2 (excluding version 2.2.2). An Arbitrary File Overwrite issue exists when extracting a tarball containing a hardlink to a file that already exists on the system, in conjunction with a later plain file with the same name as the hardlink. This plain file content replaces the existing file content. A patch has been applied to node-tar v2.2.2).

Frequently asked questions

What is CVE-2018-20834?: A vulnerability was found in node-tar before version 4.4.2 (excluding version 2.2.2). An Arbitrary File Overwrite issue exists when extracting a tarball containing a hardlink to a file that already exists on the system, in conjunction with a later plain file with the same name as the hardlink. This plain file content replaces the existing file content. A patch has been applied to node-tar v2.2.2).
How severe is CVE-2018-20834?: CVE-2018-20834 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2018-20834 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20834?: CVE-2018-20834 affects Isaacs Tar. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-20834?: 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-2018-20834 published?: CVE-2018-20834 was published on 2019-04-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:isaacs:tar:*:*:*:*:*:*:*:*

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