CVE-2026-111103

Full vulnerability record from the local CVENow database.

Description

Improper Cleanup on Thrown Exception vulnerability in the HTTP/2 handler of mtrudel bandit allows an unauthenticated remote attacker to bypass per-connection resource limits via a single TCP write that carries several frames, one of which raises a stream error. When a frame raises StreamError partway through a chunk, Bandit.HTTP2.Handler.handle_data/3 sends RST_STREAM and continues with the connection state from before the chunk, dropping the rest of it. Streams opened by earlier frames in the chunk keep running their Plug calls, but the stream counts, last_stream_id, the rapid-reset timestamps, the HPACK decoder state and the buffer roll back, so max_concurrent_streams, max_requests and the rapid-reset limiter never see those streams. A client that sends one HEADERS frame more than max_concurrent_streams in each write has the extra refused and the others forgotten: with a limit of 10, five such writes run 50 Plug calls at once. This issue affects bandit: from 1.9.0 before 1.14.0.

Severity

HIGH

CVSS score

8.2 (v4.0)

Vulnerability status

Awaiting Analysis

Source identifier

6b3ad84c-e1a6-4bf7-a703-f496b71e49db

Published

2026-10-26 14:16:27.450000

Last modified

2026-10-26 16:59:16.113000

View original CVE JSON

{
  "id": "CVE-2026-111103",
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "published": "2026-10-26T14:16:27.450",
  "lastModified": "2026-10-26T16:59:16.113",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Improper Cleanup on Thrown Exception vulnerability in the HTTP/2 handler of mtrudel bandit allows an unauthenticated remote attacker to bypass per-connection resource limits via a single TCP write that carries several frames, one of which raises a stream error.\n\nWhen a frame raises StreamError partway through a chunk, Bandit.HTTP2.Handler.handle_data/3 sends RST_STREAM and continues with the connection state from before the chunk, dropping the rest of it. Streams opened by earlier frames in the chunk keep running their Plug calls, but the stream counts, last_stream_id, the rapid-reset timestamps, the HPACK decoder state and the buffer roll back, so max_concurrent_streams, max_requests and the rapid-reset limiter never see those streams. A client that sends one HEADERS frame more than max_concurrent_streams in each write has the extra refused and the others forgotten: with a limit of 10, five such writes run 50 Plug calls at once.\n\nThis issue affects bandit: from 1.9.0 before 1.14.0."
    }
  ],
  "affected": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "affectedData": [
        {
          "vendor": "mtrudel",
          "product": "bandit",
          "defaultStatus": "unaffected",
          "collectionURL": "https://repo.hex.pm",
          "packageName": "bandit",
          "cpes": [
            "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"
          ],
          "repo": "https://github.com/mtrudel/bandit",
          "packageURL": "pkg:hex/bandit",
          "versions": [
            {
              "version": "1.9.0",
              "lessThan": "1.14.0",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "mtrudel",
          "product": "bandit",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com",
          "packageName": "mtrudel/bandit",
          "cpes": [
            "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"
          ],
          "repo": "https://github.com/mtrudel/bandit",
          "packageURL": "pkg:github/mtrudel/bandit",
          "versions": [
            {
              "version": "3ad49c80c268891e7cc412e69649115456638e59",
              "lessThan": "220b9dfd27f9a21305be2afc75cbe585ddc24e7a",
              "versionType": "git",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-26T15:11:27.499001Z",
          "id": "CVE-2026-111103",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-460"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://cna.erlef.org/cves/CVE-2026-111103.html",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/mtrudel/bandit/commit/3ad49c80c268891e7cc412e69649115456638e59",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/mtrudel/bandit/security/advisories/GHSA-2238-pgfc-w82m",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-111103",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
  ]
}