CVE-2023-29530: Laminas Diactoros provides PSR HTTP Message implementations

This month

HIGH 7.5REMOTEUPGRADEUPGRADEMITIGATE

CVE-2023-29530 is a high-severity flaw (CVSS 7.5) affecting laminas-diactoros, psr-7, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Laminas Diactoros provides PSR HTTP Message implementations. In versions 2.18.0 and prior, 2.19.0, 2.20.0, 2.21.0, 2.22.0, 2.23.0, 2.24.0, and 2.25.0, users who create HTTP requests or responses using laminas/laminas-diactoros, when providing a newline at the start or end of a header key or value, can cause an invalid message. This can lead to denial of service vectors or application errors. The problem has been patched in following versions 2.18

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 38%)
CISA exploited list	No
Weakness	CWE-20
Published	2023-04-24
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: fedoraproject · getlaminas · guzzlephp

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

Am I affected?

Timeline

2023-04-24 20:15 UTCPublished CVE record published
2026-06-17 05:50 UTCUpdated Record last modified

getlaminas laminas-diactoros UPGRADE

Affected: < 2.18.1 · 2.19.0 · 2.20.0 · 2.21.0 · 2.22.0 · 2.23.0 · 2.24.0 · 2.25.0

Fixed in: 2.18.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy laminas-diactoros || rpm -q laminas-diactoros || laminas-diactoros --version

2. UPGRADE to 2.18.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade laminas-diactoros

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade laminas-diactoros

Note

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

guzzlephp psr-7 UPGRADE

Affected: < 1.9.1 · >= 2.0.0 and < 2.4.5

Fixed in: 1.9.1, 2.4.5

Safe to downgrade to: a release before 2.0.0

1. Check installed version

apt-cache policy psr-7 || rpm -q psr-7 || psr-7 --version

2. UPGRADE to 1.9.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade psr-7

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade psr-7

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 2.0.0 (Debian / Ubuntu)

apt-cache madison psr-7 sudo apt install psr-7=<VERSION_BEFORE_2.0.0> sudo apt-mark hold psr-7

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

dnf --showduplicates list psr-7 sudo dnf downgrade psr-7-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add psr-7

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: 38

Fixed in: no fixed release known

Safe to downgrade to: a release before 38

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.

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-2023-29530?

laminas-diactoros: upgrade to 2.18.1; psr-7: upgrade to 1.9.1, 2.4.5; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-29530 being exploited?

CVE-2023-29530 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-2023-29530 affect?

CVE-2023-29530 affects laminas-diactoros, psr-7, fedora. Severity is high (CVSS 7.5). Laminas Diactoros provides PSR HTTP Message implementations. In versions 2.18.0 and prior, 2.19.0, 2.20.0, 2.21.0, 2.22.0, 2.23.0, 2.24.0, and 2.25.0, users who create HTTP requests or responses using laminas/laminas-diactoros, when providi

How urgent is CVE-2023-29530?

Priority 47/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2022-31109 HIGH 7.2 UPGRADE laminas-diactoros is a PHP package containing implementations of the PSR-7 HTTP message interfaces and PSR-17

References

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