---
title: "CVE-2018-9918\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2018-9918?format=md
keywords: index, follow
---

# CVE-2018-9918

Publication date 10 April 2018

Last updated 25 August 2025

---

Ubuntu priority

**Low**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**7.8 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2018-9918?format=md#impact-score)

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## Description

libqpdf.a in QPDF through 8.0.2 mishandles certain "expected dictionary key
but found non-name object" cases, allowing remote attackers to cause a
denial of service (stack exhaustion), related to the QPDFObjectHandle and
QPDF\_Dictionary classes, because nesting in direct objects is not
restricted.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| qpdf | 18.04 LTS bionic | Not affected |
| 17.10 artful | Fixed 8.0.2-3~17.10.1 |
| 16.04 LTS xenial | Fixed 8.0.2-3~16.04.1 |
| 14.04 LTS trusty | Fixed 8.0.2-3~14.04.1 |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2018-9918?format=md#patch-details)

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| qpdf | * Upstream:   [b4d6cf6](https://github.com/qpdf/qpdf/commit/b4d6cf6836ce025ba1811b7bbec52680c7204223) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.8 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Local |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | Required |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.8 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-9918)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-9918)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-9918)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-9918)

### Related Ubuntu Security Notices (USN)

+ [USN-3638-1](https://usn.ubuntu.com/USN-3638-1)
+ QPDF vulnerabilities
+ 7 May 2018

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2018-9918>