CVE-2020-8231 Use after free in https://github.com/curl/curl

High 7.5 Published 14 Dec 2020 Updated 14 Oct 2026

A dangling pointer in libcurl allows attackers to send data over the wrong connection, potentially leading to data leakage or modification.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2020-8231?

CVE-2020-8231 is a high-severity use after free vulnerability in Debian Debian Linux, published on 14 Dec 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

Weakness: CWE-416

Which versions are affected by CVE-2020-8231?

It affects 5 products.

Linux distribution packages (11)

`curl` SUSE:Linux Enterprise Module for Basesystem 15 SP1	All versions	`7.60.0-3.32.1`
`curl` SUSE:Linux Enterprise Module for Basesystem 15 SP2	All versions	`7.66.0-4.6.1`
`curl-openssl1` SUSE:Linux Enterprise Server 11-SECURITY	All versions	`7.37.0-70.52.2`
`curl` SUSE:Linux Enterprise Server 12 SP5	All versions	`7.60.0-11.6.1`
`curl` SUSE:Linux Enterprise Server for SAP Applications 12 SP5	All versions	`7.60.0-11.6.1`
`curl` SUSE:Linux Enterprise Software Development Kit 12 SP5	All versions	`7.60.0-11.6.1`
`curl` openSUSE:Leap 15.1	All versions	`7.60.0-lp151.5.15.1`
`curl-mini` openSUSE:Leap 15.1	All versions	`7.60.0-lp151.5.15.1`
`curl` openSUSE:Leap 15.2	All versions	`7.66.0-lp152.3.6.1`
`curl` openSUSE:Leap 15.2	All versions	`7.66.0-lp152.3.9.1`
`curl-mini` openSUSE:Leap 15.2	All versions	`7.66.0-lp152.3.9.1`

Products include Debian Debian Linux, Haxx Libcurl, Oracle Communications Cloud Native Core Policy, Siemens Sinec Infrastructure Network Services, Splunk Universal Forwarder.

How do I fix CVE-2020-8231?

Upgrade to a fixed version.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2020-8231 being exploited?

There is no known exploitation of CVE-2020-8231 in the wild and no public exploit code.

All Debian Debian Linux vulnerabilities

Sources

Also known as ALPINE-CVE-2020-8231, CLEANSTART-2026-AU97762, CURL-CVE-2020-8231, DEBIAN-CVE-2020-8231, DLA-2382-1, ECHO-79db-f588-8d3f and 12 more.