No exploitation reportedFix available

CVE-2023-29197

Q: Is CVE-2023-29197 actively exploited?

Active exploitation of CVE-2023-29197 has not been confirmed. Its EPSS score was 1.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2023-29197?

CVE-2023-29197 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

No exploitation reported by the sources we read.

Published2023-04-17
WeaknessCWE-436

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC

2023-04-1722:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-29197?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-29197?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Fedoraproject fedora

Branch	Affected	Fixed in	Source
37.x	= 37	no fix published	NVD
38.x	= 38	no fix published	NVD

Guzzlephp psr-7

Branch	Affected	Fixed in	Source
2.x	≥ 2.0.0, < 2.4.5	2.4.5	NVD · OSV
1.9	< 1.9.1	1.9.1	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

github.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.15.3read 2026-10-23
NVDCVSS 3.17.5read 2026-10-23
CNAweakness (CWE)CWE-436read 2026-10-23
FIRST EPSSEPSS score1.2 %2026-10-22
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Published: 2023-04-17
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2023-29197?

Is CVE-2023-29197 actively exploited?

Active exploitation of CVE-2023-29197 has not been confirmed. Its EPSS score was 1.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-29197?

CVE-2023-29197 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

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Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

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