How severe is CVE-2018-1000300?

CVE-2018-1000300 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-1000300 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-1000300?

CVE-2018-1000300 primarily affects Haxx Curl. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-1000300?

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-2018-1000300 published?

CVE-2018-1000300 was published on 2018-05-24 and last updated on 2026-06-17.

CVE-2018-1000300

CVE-2018-1000300 is a critical-severity vulnerability in Haxx Curl with a CVSS 3.x base score of 9.8. 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Haxx Curl
Published: 2018-05-24
Last modified: 2026-06-17

Description

curl version curl 7.54.1 to and including curl 7.59.0 contains a CWE-122: Heap-based Buffer Overflow vulnerability in denial of service and more that can result in curl might overflow a heap based memory buffer when closing down an FTP connection with very long server command replies.. This vulnerability appears to have been fixed in curl < 7.54.1 and curl >= 7.60.0.

Frequently asked questions

What is CVE-2018-1000300?: curl version curl 7.54.1 to and including curl 7.59.0 contains a CWE-122: Heap-based Buffer Overflow vulnerability in denial of service and more that can result in curl might overflow a heap based memory buffer when closing down an FTP connection with very long server command replies.. This vulnerability appears to have been fixed in curl < 7.54.1 and curl >= 7.60.0.
How severe is CVE-2018-1000300?: CVE-2018-1000300 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-1000300 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-1000300?: CVE-2018-1000300 primarily affects Haxx Curl. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-1000300?: 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-2018-1000300 published?: CVE-2018-1000300 was published on 2018-05-24 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:17.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*

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