CVE-2026-115877

Full vulnerability record from the local CVENow database.

Description

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.web.http.HTTPChannel.headerReceived rejects a NUL byte in an HTTP header value but accepts a bare carriage return or bare line feed. Because Twisted splits header lines only on CRLF, a hidden Content-Length header can remain folded into another value while a lenient front end treats the bare character as a line terminator. The resulting framing disagreement can smuggle a following request past front-end access controls, poison a shared connection or cache, and expose a later client to the wrong response. This issue is an incomplete-fix residual of earlier Twisted request-smuggling protections. This issue is fixed in version 26.10.0rc1.

Severity

MEDIUM

CVSS score

5.4 (v3.1)

Vulnerability status

Awaiting Analysis

Source identifier

[email protected]

Published

2026-10-23 21:17:23.643000

Last modified

2026-10-29 15:17:19.207000

View original CVE JSON

{
  "id": "CVE-2026-115877",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-23T21:17:23.643",
  "lastModified": "2026-10-29T15:17:19.207",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.web.http.HTTPChannel.headerReceived rejects a NUL byte in an HTTP header value but accepts a bare carriage return or bare line feed. Because Twisted splits header lines only on CRLF, a hidden Content-Length header can remain folded into another value while a lenient front end treats the bare character as a line terminator. The resulting framing disagreement can smuggle a following request past front-end access controls, poison a shared connection or cache, and expose a later client to the wrong response. This issue is an incomplete-fix residual of earlier Twisted request-smuggling protections. This issue is fixed in version 26.10.0rc1."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "twisted",
          "product": "twisted",
          "versions": [
            {
              "version": "< 26.10.0rc1",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N",
          "baseScore": 5.4,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 2.7
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-29T14:21:44.755036Z",
          "id": "CVE-2026-115877",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-444"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/twisted/twisted/commit/022b6f7feb5980166c71f54e2c0d8f4f21ff6e1a",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/twisted/twisted/commit/1616f702d36eda8990a5a5b22ad70fab140a7eb1",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/twisted/twisted/pull/12755",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/twisted/twisted/security/advisories/GHSA-q7qq-6mhp-9rc4",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/twisted/twisted/security/advisories/GHSA-q7qq-6mhp-9rc4",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}