CVE-2022-43552: A use after free vulnerability exists in curl <7.87.0

Q: How urgent is CVE-2022-43552?

Priority 52/100. Public exploit reference; Remotely exploitable, no login, no user action

This week

MEDIUM 5.9REMOTEUPGRADEUPGRADEUPGRADE

CVE-2022-43552 is a medium-severity flaw (CVSS 5.9) affecting curl, macos, universal forwarder. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A use after free vulnerability exists in curl <7.87.0. Curl can be asked to *tunnel* virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the specific protocols SMB or TELNET, curl would use a heap-allocated struct after it had been freed, in its transfer shutdown code path.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-416
Published	2023-02-09
Last modified	2026-10-23

Publisher (CNA): HackerOne · Vendor: apple · haxx · splunk

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-02-09 20:15 UTCPublished CVE record published
2026-10-23 23:10 UTCUpdated Record last modified

haxx curl UPGRADE

Affected: < 7.87.0

Fixed in: 7.87.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy curl || rpm -q curl || curl --version

2. UPGRADE to 7.87.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade curl

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade curl

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

apple macos UPGRADE

Affected: >= 13.0 and < 13.3

Fixed in: 13.3

Safe to downgrade to: a release before 13.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

splunk universal forwarder UPGRADE

Affected: >= 8.2.0 and < 8.2.12 · >= 9.0.0 and < 9.0.6 · 9.1.0

Fixed in: 8.2.12, 9.0.6

Safe to downgrade to: a release before 8.2.0

1. Check installed version

apt-cache policy universal-forwarder || rpm -q universal-forwarder || universal-forwarder --version

2. UPGRADE to 8.2.12 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade universal-forwarder

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade universal-forwarder

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 8.2.0 (Debian / Ubuntu)

apt-cache madison universal-forwarder sudo apt install universal-forwarder=<VERSION_BEFORE_8.2.0> sudo apt-mark hold universal-forwarder

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list universal-forwarder sudo dnf downgrade universal-forwarder-<VERSION_BEFORE_8.2.0> sudo dnf versionlock add universal-forwarder

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · python-openslide · FIXED · 1.4.7-1.fc46 · FEDORA-2026-336bea884e · source

sudo dnf upgrade --advisory=FEDORA-2026-336bea884e

Fedora ELN · valgrind · FIXED · 3.28.0-1.eln159 · FEDORA-2026-c593ef1d15 · source

sudo dnf upgrade --advisory=FEDORA-2026-c593ef1d15

Ubuntu 20.04 · curl · FIXED · 7.68.0-1ubuntu2.15

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.68.0-1ubuntu2.15" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · curl · FIXED · 7.81.0-1ubuntu1.7

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.81.0-1ubuntu1.7" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · curl · FIXED · 7.86.0-3

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.86.0-3" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · curl · FIXED · 7.86.0-3

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.86.0-3" && echo PATCHED || echo STILL-VULNERABLE

RHEL 7 · curl · FIXED · curl-7.29.0-59.el7_9.2

sudo dnf upgrade --advisory=RHSA-2023:7743 rpm -q curl

RHEL 8 · curl · FIXED · curl-7.61.1-30.el8

sudo dnf upgrade --advisory=RHSA-2023:2963 rpm -q curl

RHEL 8.6 Extended Update Support · curl · FIXED · curl-7.61.1-22.el8_6.12

sudo dnf upgrade --advisory=RHSA-2024:0428 rpm -q curl

RHEL 9 · curl · FIXED · curl-7.76.1-23.el9

sudo dnf upgrade --advisory=RHSA-2023:2478 rpm -q curl

RHEL 6 · curl · DEFERRED

Alpine 3.20 · curl · FIXED · curl-7.87.0-r0

apk add --upgrade curl apk info -v curl

Alpine 3.21 · curl · FIXED · curl-7.87.0-r0

apk add --upgrade curl apk info -v curl

Alpine 3.22 · curl · FIXED · curl-7.87.0-r0

apk add --upgrade curl apk info -v curl

Alpine 3.23 · curl · FIXED · curl-7.87.0-r0

apk add --upgrade curl apk info -v curl

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2023-083 · source

sudo dnf update --advisory=ALAS2023-2023-083

Amazon Linux 2 · see advisory · FIXED · ALAS2-2023-1924 · source

sudo yum update --advisory=ALAS2-2023-1924

Amazon Linux 1 · see advisory · FIXED · ALAS-2023-1729 · source

sudo yum update --advisory=ALAS-2023-1729

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2022-43552?

curl: upgrade to 7.87.0; macos: upgrade to 13.3; universal forwarder: upgrade to 8.2.12, 9.0.6. Exact commands for each OS are on this page.

Is CVE-2022-43552 being exploited?

CVE-2022-43552 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2022-43552 affect?

CVE-2022-43552 affects curl, macos, universal forwarder. Severity is medium (CVSS 5.9). A use after free vulnerability exists in curl <7.87.0. Curl can be asked to *tunnel* virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the s

How urgent is CVE-2022-43552?

Priority 52/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

macOS vulnerabilities · curl vulnerabilities · Splunk vulnerabilities

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References

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