CVE-2023-24807 is a high-severity inefficient regular expression (ReDoS) vulnerability in undici (npm), affecting versions < 5.19.1. It is fixed in 5.19.1.
Impact The Headers.set() and Headers.append() methods are vulnerable to Regular Expression Denial of Service (ReDoS) attacks when untrusted values are passed into the functions. This is due to the inefficient regular expression used to normalize the values in the headerValueNormalize() utility function. Patches This vulnerability was patched in v5.19.1. Workarounds There is no workaround. Please update to an unaffected version. References https://hackerone.com/bugs?report_id=1784449 Credits Carter Snook reported this vulnerability.
A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use. Typical impact: denial of service when input is crafted to trigger backtracking.
CVE-2023-24807 has a CVSS score of 7.5 (High). 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 (5.19.1). Upgrading removes the vulnerable code path.
npm
undici (< 5.19.1)undici → 5.19.1 (npm)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-2023-24807 is reachable in your applications. Explore open-source security for your team.
See if CVE-2023-24807 is reachable in your applications. Get a demo
Upgrade undici to 5.19.1 or later to resolve this vulnerability.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2023-24807 is a high-severity inefficient regular expression (ReDoS) vulnerability in undici (npm), affecting versions < 5.19.1. It is fixed in 5.19.1. A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use.
CVE-2023-24807 has a CVSS score of 7.5 (High). 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.
undici (npm) versions < 5.19.1 is affected.
Yes. CVE-2023-24807 is fixed in 5.19.1. Upgrade to this version or later.
Whether CVE-2023-24807 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.
Upgrade undici to 5.19.1 or later.