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CVE-2026-110353

Full vulnerability record from the local CVENow database.

Description

HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-10-22 03:16:31.270000
Last modified
2026-10-22 19:17:35.540000
View original CVE JSON
{
  "id": "CVE-2026-110353",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-22T03:16:31.270",
  "lastModified": "2026-10-22T19:17:35.540",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "HAProxy",
          "product": "HAProxy",
          "defaultStatus": "unaffected",
          "modules": [
            "mux-h2"
          ],
          "programFiles": [
            "src/mux_h2.c"
          ],
          "programRoutines": [
            {
              "name": "h2c_handle_ping"
            }
          ],
          "repo": "https://git.haproxy.org/git/haproxy.git/",
          "versions": [
            {
              "version": "3.2.0",
              "lessThan": "3.2.26",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "3.3.0",
              "lessThan": "3.3.17",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "3.4.0",
              "lessThan": "3.4.6",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "3.5-dev",
              "lessThan": "3.5-dev9",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "HAProxy",
          "product": "HAProxy Enterprise Edition",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "3.2.0r1",
              "lessThan": "3.2r1-378.1259",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "3.3.0r1",
              "lessThan": "3.3r1-377.1005",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "HAProxy",
          "product": "Kubernetes Ingress Controller",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "3.2.0",
              "lessThan": "3.2.17",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Haproxy",
          "product": "Kubernetes Ingress Controller Enterprise",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "3.2.0",
              "lessThan": "3.2.17-ee1",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "3.0",
              "lessThan": "3.0.16-ee17",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "1.11",
              "lessThan": "1.11.14-ee11",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-22T13:42:53.833295Z",
          "id": "CVE-2026-110353",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-252"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.haproxy.org/?p=haproxy.git;a=commit;h=cec63e95f62a7412484f1134f5aa227e5b7e1466",
      "source": "[email protected]"
    }
  ]
}