CVE-2023-44386: Vapor is an HTTP web framework for Swift

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2023-44386 is a medium-severity flaw (CVSS 5.3) affecting vapor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Vapor is an HTTP web framework for Swift. There is a denial of service vulnerability impacting all users of affected versions of Vapor. The HTTP1 error handler closed connections when HTTP parse errors occur instead of passing them on. The issue is fixed as of Vapor release 4.84.2.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 46%)
CISA exploited list	No
Weakness	CWE-231, CWE-617, CWE-696
Published	2023-10-05
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: vapor

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-10-05 18:15 UTCPublished CVE record published
2026-06-17 06:27 UTCUpdated Record last modified

vapor vapor UPGRADE

Affected: >= 4.83.2 and < 4.84.2

Fixed in: 4.84.2

Safe to downgrade to: a release before 4.83.2

1. Check installed version

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

2. UPGRADE to 4.84.2 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade vapor

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 4.83.2 (Debian / Ubuntu)

apt-cache madison vapor sudo apt install vapor=<VERSION_BEFORE_4.83.2> sudo apt-mark hold vapor

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

dnf --showduplicates list vapor sudo dnf downgrade vapor-<VERSION_BEFORE_4.83.2> sudo dnf versionlock add vapor

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.

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-2023-44386?

vapor: upgrade to 4.84.2. Exact commands for each OS are on this page.

Is CVE-2023-44386 being exploited?

CVE-2023-44386 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-2023-44386 affect?

CVE-2023-44386 affects vapor. Severity is medium (CVSS 5.3). Vapor is an HTTP web framework for Swift. There is a denial of service vulnerability impacting all users of affected versions of Vapor. The HTTP1 error handler closed connections when HTTP parse errors occur instead of passing them on. The

How urgent is CVE-2023-44386?

Priority 37/100. Remotely exploitable, no login, no user action

Software pages

Swift vulnerabilities

Related CVEs

CVE-2024-21631 MEDIUM 6.5 UPGRADE Vapor is an HTTP web framework for Swift
CVE-2022-31019 HIGH 7.5 UPGRADE Vapor is a server-side Swift HTTP web framework
CVE-2022-31005 HIGH 7.5 UPGRADE Vapor is an HTTP web framework for Swift
CVE-2021-32742 HIGH 7.5 UPGRADE Vapor is a web framework for Swift
CVE-2021-21328 MEDIUM 5.3 UPGRADE Vapor is a web framework for Swift

References

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