Summary
All versions of @hapi/content through 6.0.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via crafted HTTP header values. Three regular expressions used to parse Content-Type and Content-Disposition headers contain patterns susceptible to catastrophic backtracking. This has been fixed in v6.0.1.
Workarounds
There are no known workarounds. Upgrade to the patched version.
Impact
Denial of Service. An unauthenticated remote attacker can cause a Node.js process to become unresponsive by sending a single HTTP request with a maliciously crafted header value.
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-2026-35213 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 (6.0.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Fixed by tightening all three regular expressions to eliminate backtracking.
Frequently Asked Questions
- What is CVE-2026-35213? CVE-2026-35213 is a high-severity inefficient regular expression (ReDoS) vulnerability in @hapi/content (npm), affecting versions <= 6.0.0. It is fixed in 6.0.1. A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use.
- How severe is CVE-2026-35213? CVE-2026-35213 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.
- Which versions of @hapi/content are affected by CVE-2026-35213? @hapi/content (npm) versions <= 6.0.0 is affected.
- Is there a fix for CVE-2026-35213? Yes. CVE-2026-35213 is fixed in 6.0.1. Upgrade to this version or later.
- Is CVE-2026-35213 exploitable, and should I be worried? Whether CVE-2026-35213 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
- What actually determines whether CVE-2026-35213 is exploitable, and how bad it is? 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.
- How do I fix CVE-2026-35213? Upgrade
@hapi/contentto 6.0.1 or later.