CVE-2023-29197 is a medium-severity security vulnerability in guzzlehttp/psr7 (composer), affecting versions < 1.9.1. It is fixed in 1.9.1, 2.4.5.
Impact 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. Patches The issue is patched in 1.9.1 and 2.4.5. Workarounds There are no known workarounds. References https://www.rfc-editor.org/rfc/rfc7230#section-3.2.4
CVE-2023-29197 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (1.9.1, 2.4.5). Upgrading removes the vulnerable code path.
composer
guzzlehttp/psr7 (< 1.9.1)guzzlehttp/psr7 (>= 2.0.0, < 2.4.5)guzzlehttp/psr7 → 1.9.1 (composer)guzzlehttp/psr7 → 2.4.5 (composer)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2023-29197 is reachable in your applications. Explore open-source security for your team.
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Upgrade the following packages to resolve this vulnerability:
guzzlehttp/psr7 to 1.9.1 or laterguzzlehttp/psr7 to 2.4.5 or laterKodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2023-29197 is a medium-severity security vulnerability in guzzlehttp/psr7 (composer), affecting versions < 1.9.1. It is fixed in 1.9.1, 2.4.5.
CVE-2023-29197 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
guzzlehttp/psr7 (composer) versions < 1.9.1 is affected.
Yes. CVE-2023-29197 is fixed in 1.9.1, 2.4.5. Upgrade to this version or later.
Whether CVE-2023-29197 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
guzzlehttp/psr7 to 1.9.1 or laterguzzlehttp/psr7 to 2.4.5 or later