How severe is CVE-2018-18020?

CVE-2018-18020 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2018-18020 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-18020?

CVE-2018-18020 affects Qpdf Project Qpdf. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-18020?

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

When was CVE-2018-18020 published?

CVE-2018-18020 was published on 2018-10-06 and last updated on 2026-06-17.

CVE-2018-18020

CVE-2018-18020 is a low-severity vulnerability in Qpdf Project Qpdf with a CVSS 3.x base score of 3.3. 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-674.

Key facts

Severity: Low (CVSS 3.x base score 3.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-674
Affected product: Qpdf Project Qpdf
Published: 2018-10-06
Last modified: 2026-06-17

Description

In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and QPDFWriter::unparseChild have recursive calls for a long time, which allows remote attackers to cause a denial of service via a crafted PDF file.

Frequently asked questions

What is CVE-2018-18020?: In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and QPDFWriter::unparseChild have recursive calls for a long time, which allows remote attackers to cause a denial of service via a crafted PDF file.
How severe is CVE-2018-18020?: CVE-2018-18020 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2018-18020 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-18020?: CVE-2018-18020 affects Qpdf Project Qpdf. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-18020?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-18020 published?: CVE-2018-18020 was published on 2018-10-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:qpdf_project:qpdf:8.2.1:*:*:*:*:*:*:*

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