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Fencer Vulns
medium 5.3

CVE-2023-29197 json

Improper header name validation in guzzlehttp/psr7

published 2023-04-17 3 y ago modified 2026-06-17 4 mo ago also GHSA-wxmh-65f7-jcvw , EUVD-2023-1416

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

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.

Patch / fix

  • packagist guzzlehttp/psr7 1.9.1, 2.4.5
  • guzzlephp psr-7 1.9.1, 2.4.5
  • php-nyholm-psr7 Debian 14, Debian 13, Debian 12 1.5.1-2
  • php-guzzlehttp-psr7 Debian 14, Debian 13, Debian 12 2.4.5-1

debian advisories DEBIAN-CVE-2023-29197

  • php-guzzlehttp-psr7 Ubuntu 20.04 LTS 1.4.2-0.1+deb10u2build0.20.04.1
  • php-nyholm-psr7 Ubuntu Pro 22.04 LTS 1.5.0-1ubuntu0.1~esm1
  • php-guzzlehttp-psr7 Ubuntu Pro 22.04 LTS 1.8.3-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2023-29197

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-29197 updated cvss 5.3

guzzlehttp/psr7: Improper header validation in guzzlehttp/psr7

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.22% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
packagist guzzlehttp/psr7
<1.9.1
>=2.0.0, <2.4.5
1.9.1
2.4.5

Affected products

  • guzzle psr7

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.