CVE-2023-23916: An allocation of resources without limits or throttling vulnerability exists in curl <v7.88.0 based on the "ch

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MEDIUM 6.5WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2023-23916 is a medium-severity flaw (CVSS 6.5) affecting curl, fedora, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An allocation of resources without limits or throttling vulnerability exists in curl <v7.88.0 based on the "chained" HTTP compression algorithms, meaning that a server response can be compressed multiple times and potentially with differentalgorithms. The number of acceptable "links" in this "decompression chain" wascapped, but the cap was implemented on a per-header basis allowing a maliciousserver to insert a virtually unlimited number of compr

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.7% (top 22%)
CISA exploited list	No
Weakness	CWE-770
Published	2023-02-23
Last modified	2026-10-23

Publisher (CNA): HackerOne · Vendor: debian · fedoraproject · haxx · netapp

Am I affected?

Timeline

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

haxx curl UPGRADE

Affected: >= 7.57.0 and < 7.88.0

Fixed in: 7.88.0

Safe to downgrade to: a release before 7.57.0

1. Check installed version

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

2. UPGRADE to 7.88.0 (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.

3. If no update is available yet, DOWNGRADE to a release before 7.57.0 (Debian / Ubuntu)

apt-cache madison curl sudo apt install curl=<VERSION_BEFORE_7.57.0> sudo apt-mark hold curl

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

dnf --showduplicates list curl sudo dnf downgrade curl-<VERSION_BEFORE_7.57.0> sudo dnf versionlock add curl

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.

fedoraproject fedora MITIGATE

Affected: 36

Fixed in: no fixed release known

Safe to downgrade to: a release before 36

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.

debian debian linux MITIGATE

Affected: 10.0 · 11.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.0

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.

netapp h300s firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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.

netapp h500s firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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.

netapp h700s firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

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 · 7.68.0-1ubuntu2.16

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.68.0-1ubuntu2.16" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · curl · FIXED · 7.81.0-1ubuntu1.8

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.81.0-1ubuntu1.8" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · curl · FIXED · 7.88.1-1

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.88.1-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · curl · FIXED · 7.88.1-1

sudo apt update && sudo apt install --only-upgrade curl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' curl)" ge "7.88.1-1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 8 · curl · FIXED · curl-7.61.1-25.el8_7.3

sudo dnf upgrade --advisory=RHSA-2023:1140 rpm -q curl

RHEL 8.4 Advanced Mission Critical Update Support · curl · FIXED · curl-7.61.1-18.el8_4.3

sudo dnf upgrade --advisory=RHSA-2023:3460 rpm -q curl

RHEL 8.4 Telecommunications Update Service · curl · FIXED · curl-7.61.1-18.el8_4.3

sudo dnf upgrade --advisory=RHSA-2023:3460 rpm -q curl

RHEL 8.4 Update Services for SAP Solutions · curl · FIXED · curl-7.61.1-18.el8_4.3

sudo dnf upgrade --advisory=RHSA-2023:3460 rpm -q curl

RHEL 8.6 Extended Update Support · curl · FIXED · curl-7.61.1-22.el8_6.6

sudo dnf upgrade --advisory=RHSA-2023:1842 rpm -q curl

Alpine 3.20 · curl · FIXED · curl-7.88.0-r0

apk add --upgrade curl apk info -v curl

Alpine 3.21 · curl · FIXED · curl-7.88.0-r0

apk add --upgrade curl apk info -v curl

Alpine 3.22 · curl · FIXED · curl-7.88.0-r0

apk add --upgrade curl apk info -v curl

Alpine 3.23 · curl · FIXED · curl-7.88.0-r0

apk add --upgrade curl apk info -v curl

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2023-114 · source

sudo dnf update --advisory=ALAS2023-2023-114

Amazon Linux 2 · see advisory · FIXED · ALAS2-2023-1986 · source

sudo yum update --advisory=ALAS2-2023-1986

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.

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References

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