CVE-2016-8622

What it is

The URL percent-encoding decode function in libcurl before 7.51.0 is called `curl_easy_unescape`. Internally, even if this function would be made to allocate a unscape destination buffer larger than 2GB, it would return that new length in a signed 32 bit integer variable, thus the length would get either just truncated or both truncated and turned negative. That could then lead to libcurl writing outside of its heap based buffer.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

4.7% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2018-07-31 21:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 00:54 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 4.7% in the next 30 days (EPSS).
• Severity: 3.7 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2018-07-31 21:29 UTC

Last modified

2026-06-17 00:54 UTC

Exploit probability

4.7% · EPSS, next 30 days

Weakness

CWE-122

Record status

Modified

Affected

• Haxx Libcurl < 7.51.0

Attack profile CVSS 3.0 · 3.7

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2016-8622.md and follow it. Check whether this project is affected by CVE-2016-8622. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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