FKIE_CVE-2026-42581

Vulnerability from fkie_nvd - Published: 2026-05-13 19:17 - Updated: 2026-05-18 13:14
Severity ?
5.8 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
References
security-advisories@github.comhttps://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9Exploit, Vendor Advisory, Mitigation
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9Exploit, Vendor Advisory, Mitigation
Impacted products
Vendor Product Version
netty netty *
netty netty *
To clipboard 

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  "configurations": [
    {
      "nodes": [
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              "matchCriteriaId": "DFE205A5-2C43-40C9-A2FF-CF6759B8D861",
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    }
  ],
  "id": "CVE-2026-42581",
  "lastModified": "2026-05-18T13:14:18.723",
  "metrics": {
    "cvssMetricV31": [
      {
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          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.8,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
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  "published": "2026-05-13T19:17:23.627",
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  "vulnStatus": "Analyzed",
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.