CVE-2023-29197

Name: CVE-2023-29197
Creator: NVD / NIST
Published: 2023-04-17T22:15:09.947+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.22%

Last modified Jun 17, 2026

CVE-2023-29197 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Affected versions are subject to improper header parsing. EPSS estimates a 1.22% chance of exploitation in the next 30 days.

Description

guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Affected versions are subject to improper header parsing. An attacker could sneak in a newline (\n) into both the header names and values. While the specification states that \r\n\r\n is used to terminate the header list, many servers in the wild will also accept \n\n. This is a follow-up to CVE-2022-24775 where the fix was incomplete. The issue has been patched in versions 1.9.1 and 2.4.5. There are no known workarounds for this vulnerability. Users are advised to upgrade.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

1.22%

64.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-436

Affected Software

Vendor	Product	Versions
Guzzlephp	Psr-7	< 1.9.1
Guzzlephp	Psr-7	>= 2.0.0, < 2.4.5
Fedoraproject	Fedora	37
Fedoraproject	Fedora	38

References

https://cve.mitre.org/cgi-bin/cvename.cgi?name=2022-24775Not Applicable
https://github.com/guzzle/psr7/security/advisories/GHSA-q7rv-6hp3-vh96Not Applicable
https://github.com/guzzle/psr7/security/advisories/GHSA-wxmh-65f7-jcvwVendor Advisory
https://lists.debian.org/debian-lts-announce/2023/12/msg00028.html
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FJANWDXJZE5BGLN4MQ4FEHV5LJ6CMKQF/Mailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/O35UN4IK6VS2LXSRWUDFWY7NI73RKY2U/Mailing List, Third Party Advisory
https://www.rfc-editor.org/rfc/rfc7230#section-3.2.4Technical Description
https://cve.mitre.org/cgi-bin/cvename.cgi?name=2022-24775Not Applicable
https://github.com/guzzle/psr7/security/advisories/GHSA-q7rv-6hp3-vh96Not Applicable
https://github.com/guzzle/psr7/security/advisories/GHSA-wxmh-65f7-jcvwVendor Advisory
https://lists.debian.org/debian-lts-announce/2023/12/msg00028.html
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FJANWDXJZE5BGLN4MQ4FEHV5LJ6CMKQF/Mailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/O35UN4IK6VS2LXSRWUDFWY7NI73RKY2U/Mailing List, Third Party Advisory
https://www.rfc-editor.org/rfc/rfc7230#section-3.2.4Technical Description

Timeline

Published: Apr 17, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-29197?

How severe is CVE-2023-29197?

CVE-2023-29197 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.22% probability of exploitation in the next 30 days.

How do I fix CVE-2023-29197?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-29197?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST