CVE-2018-18020
In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and QPDFWriter::unparseChild...
CVE-2018-18020 is a low vulnerability (CVSS 3.3) in Qpdf Project Qpdf, published October 6, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.21%, the 68th percentile. Fixed in qpdf 9.0.0-1.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2018-18020- CVSS 3.0
- 3.3 Low
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-674
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2018-18020- Updated
- 2026-11-02
EUVDEUVD-2018-9759 No score
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.
- Record
EUVD-2018-9759- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-r676-q927-78rr
In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and QPDFWriter::unparseChild...
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.
- Record
GHSA-r676-q927-78rr- CVSS 3.0
- 3.3 Low
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Weakness
- CWE-674
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2018-18020- CVSS 3.0
- 3.3 Low
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVDEBIAN-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.
- Record
DEBIAN-CVE-2018-18020- CVSS 3.0
- 3.3 Low
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVUBUNTU-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.
- Record
UBUNTU-CVE-2018-18020- CVSS 3.0
- 3.3 Low
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVUSN-5026-1 No score
qpdf vulnerabilities
It was discovered that QPDF incorrectly handled certain malformed PDF files. A remote attacker could use this issue to cause QPDF to consume resources, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-18020)
It was discovered that QPDF incorrectly handled certain malformed PDF files. A remote attacker could use this issue to cause QPDF to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36978)
- Record
USN-5026-1- Updated
- 2026-11-02
OSVUSN-5026-2 No score
qpdf vulnerabilities
USN-5026-1 fixed several vulnerabilities in QPDF. This update provides the corresponding update for Ubuntu 16.04 ESM. Original advisory details:
It was discovered that QPDF incorrectly handled certain malformed PDF files. A remote attacker could use this issue to cause QPDF to consume resources, resulting in a denial of service. (CVE-2018-18020)
It was discovered that QPDF incorrectly handled certain malformed PDF files. A remote attacker could use this issue to cause QPDF to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36978)
- Record
USN-5026-2- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
qpdfDebian:12 |
before 9.0.0-1 | 9.0.0-1 |
qpdfDebian:13 |
before 9.0.0-1 | 9.0.0-1 |
qpdfDebian:14 |
before 9.0.0-1 | 9.0.0-1 |
qpdfDebian:10 |
before 8.4.0-2+deb10u1, plus listed versions 8.4.0-2 |
8.4.0-2+deb10u1 |
qpdfUbuntu:Pro:16.04:LTS |
before 8.0.2-3~16.04.1+esm1, plus listed versions 5.1.3-25.1.3-35.2.0-15.2.0-26.0.0-28.0.2-3~16.04.1 |
8.0.2-3~16.04.1+esm1 |
qpdfUbuntu:18.04:LTS |
before 8.0.2-3ubuntu0.1, plus listed versions 7.0.0-17.1.0-17.1.1-18.0.0-18.0.1-18.0.2-18.0.2-3 |
8.0.2-3ubuntu0.1 |
qpdfUbuntu:20.04:LTS |
before 9.1.1-1ubuntu0.1, plus listed versions 8.4.2-19.0.2-19.1.0-19.1.1-19.1.1-1build1 |
9.1.1-1ubuntu0.1 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |