Unrated

DEBIAN-CVE-2026-59980

Type: advisorySource: OSV1 source record

hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, 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. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.

Announced 23 Sept 2026Group revision 1

Original source ↗

DEBIAN-CVE-2026-59980

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-59980

python-hpack

Source reference: /affected/0/package/name

Affected versions: 4.0.0-2
Source reference: /affected/0/versions
4.0.0-3
Source reference: /affected/0/versions
4.0.0-4
Source reference: /affected/0/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

python-hpack

Source reference: /affected/1/package/name

Affected versions: 4.0.0-3
Source reference: /affected/1/versions
4.0.0-4
Source reference: /affected/1/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

python-hpack

Source reference: /affected/2/package/name

Affected versions: 4.0.0-3
Source reference: /affected/2/versions
4.0.0-4
Source reference: /affected/2/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "python-hpack",
      "purl": "pkg:deb/debian/python-hpack?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "4.0.0-2",
      "4.0.0-3",
      "4.0.0-4"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-59980.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "python-hpack",
      "purl": "pkg:deb/debian/python-hpack?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "4.0.0-3",
      "4.0.0-4"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-59980.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "python-hpack",
      "purl": "pkg:deb/debian/python-hpack?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "4.0.0-3",
      "4.0.0-4"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-59980.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #59414 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 18:28:44 GMT
Publisher date: Wed, 23 Sep 2026 23:17:11 GMT

Read the original announcement

Revision history

25 Oct 2026DEBIAN-CVE-2026-59980 · Revision 1Source updated