In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and…
Priority LOW 18CWE-674Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-674.
Summary
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.
Why it matters now
EPSS 0.01209 68th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Deferred Red Hat: fix deferred
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:qpdf_project:qpdf:8.2.1:*:*:*:*:*:*:* | 8.2.1 | Vulnerable | Qpdf Project |
- cpe:2.3:a:qpdf_project:qpdf:8.2.1:*:*:*:*:*:*:* Versions 8.2.1 Vulnerable ·Qpdf Project
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2018-18020
- 2026-10-03 Alias added: GHSA-r676-q927-78rr
References
More Qpdf Project Qpdf vulnerabilities
- TI-2024-16045 Heap Buffer Overflow vulnerability in qpdf 11.9.0 allows attackers to crash the… CVSS 3.1MEDIUM 5.5
- TI-2021-07868 An issue was discovered in QPDF version 10.0.4, allows remote attackers to execute… CVSS 3.1MEDIUM 5.3
- TI-2017-09321 The tokenizer in QPDF 6.0.0 and 7.0.b1 is recursive for arrays and dictionaries, which… CVSS 3.0HIGH 7.8
- TI-2018-07028 libqpdf.a in QPDF through 8.0.2 mishandles certain "expected dictionary key but found… CVSS 3.0HIGH 7.8
- TI-2022-15389 QPDF v8.4.2 was discovered to contain a heap buffer overflow via the function… CVSS 3.1MEDIUM 6.5
- TI-2017-06661 libqpdf.a in QPDF 6.0.0 allows remote attackers to cause a denial of service (infinite… CVSS 3.0MEDIUM 5.5
Sources
- CVE-2018-18020 · CVE Program
- CVE-2018-18020 · NVD
- FIRST EPSS
- GHSA-r676-q927-78rr · GitHub Advisory Database · CC BY 4.0
- CVE-2018-18020 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences