# CVE-2016-9842: Integer overflow in n/a

> Attackers might exploit left shifts of negative integers in zlib's inflateMark function, potentially causing unspecified impacts.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 23 May 2017
- **Updated:** 14 Jul 2026
- **Also known as:** ALPINE-CVE-2016-9842, AZL-44631, AZL-45183, DEBIAN-CVE-2016-9842, GHSA-3686-jjcf-4w27, MINI-fhpr-gwrx-f937, PSF-2017-4, UBUNTU-CVE-2016-9842

## What is CVE-2016-9842?

CVE-2016-9842 is a high-severity vulnerability in Apple Iphone Os, published on 23 May 2017. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The inflateMark function in inflate.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving left shifts of negative integers.

Weakness: CWE-1335 (Incorrect Bitwise Shift of Integer)

## Which versions are affected by CVE-2016-9842?

It affects 19 products.


Products: Apple Iphone Os, Apple Mac Os X, Apple Tvos, Apple Watchos, Canonical Ubuntu Linux, Debian Debian Linux, Nodejs Node.js, Opensuse Leap, Opensuse Opensuse, Oracle Database Server, Oracle Jdk, Oracle Jre, Oracle Mysql, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Eus, Redhat Enterprise Linux Server, Redhat Enterprise Linux Workstation, Redhat Satellite, Zlib Zlib.

## How do I fix CVE-2016-9842?

Upgrade to a fixed version.

## Is CVE-2016-9842 being exploited?

There is no known exploitation of CVE-2016-9842 in the wild and no public exploit code.

## Other vulnerabilities in Apple Iphone Os

- [CVE-2021-30666](https://insights.sbomify.com/CVE-2021-30666/): Apple iOS WebKit Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2021-30761](https://insights.sbomify.com/CVE-2021-30761/): Apple iOS WebKit Memory Corruption (high 8.8, exploited in the wild)
- [CVE-2021-30762](https://insights.sbomify.com/CVE-2021-30762/): Apple iOS WebKit Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2016-4657](https://insights.sbomify.com/CVE-2016-4657/): Apple iOS Webkit Memory Corruption (high 8.8, exploited in the wild)
- [CVE-2019-7286](https://insights.sbomify.com/CVE-2019-7286/): Apple Multiple Products Memory Corruption (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9842 and fix it if it is affected.

What it is: CVE-2016-9842 is a high-severity vulnerability in Apple Iphone Os, published on 23 May 2017. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2016-9842 in the wild and no public exploit code.

Affected product: Apple Iphone Os. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2016-9842/ (Markdown: https://insights.sbomify.com/CVE-2016-9842/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9842
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9842
- OSV: https://osv.dev/vulnerability/CVE-2016-9842

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-9842/
Summaries are generated and may contain mistakes; the official description above is the record.