BREW-PROWLER-CVE-2026-59980 (GHSA-8V8H-HG4W-MVQ2)

Vulnerability from osv_homebrew – Published: 2026-09-25 10:06 – Updated: 2026-09-25 10:06 – Source website
VLAI
Summary
hpack: Unbounded variable integer decoding can cause run-away computation on malformed input
Details

Impact

Users of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). Unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input.

Patches

A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.

Workarounds

Sanitize input to hpack decoder for long sequences of 0xFF values to prevent malicious use.

Severity
6.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "hpack",
        "resource_purl": "pkg:pypi/hpack@4.2.0",
        "upstream_fixed_in": "4.2.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "prowler",
        "purl": "pkg:brew/prowler"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.13.0"
            },
            {
              "fixed": "5.31.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/hpack@4.2.0",
        "name": "hpack",
        "resource": "hpack",
        "strategy": "registry",
        "subject_version": "4.2.0"
      }
    ]
  },
  "details": "### Impact\n\nUsers of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). Unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input.\n\n### Patches\nA fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.\n\n### Workarounds\nSanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.",
  "id": "BREW-prowler-CVE-2026-59980",
  "modified": "2026-09-25T10:06:48Z",
  "published": "2026-09-25T10:06:48Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/python-hyper/hpack/security/advisories/GHSA-8v8h-hg4w-mvq2"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59980"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-hyper/hpack/commit/8cfb02c547740e16dbfe7aba77bad84b297cec2c"
    },
    {
      "type": "WEB",
      "url": "https://cs.opensource.google/go/x/net/+/master:http2/hpack/hpack.go;l=468;drc=8e2b117aee74f6b86c207a808b0255de45c0a18a"
    },
    {
      "type": "WEB",
      "url": "https://docs.rs/http2/0.5.19/src/http2/hpack/decoder.rs.html#403"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/python-hyper/hpack"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python-hyper/hpack/releases/tag/v4.2.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "hpack: Unbounded variable integer decoding can cause run-away computation on malformed input",
  "upstream": [
    "GHSA-8v8h-hg4w-mvq2",
    "CVE-2026-59980"
  ]
}



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