python-urllib3 — security advisory

{
  "id": "62fc03969de443746db3734250b990e68ee4352829c06b5a4c5147d5b991b837",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-97688",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2026-97688",
    "summary": "urllib3 is an HTTP client library for Python. From 2.6.2 until 2.8.0, HTTPResponse.stream and HTTPResponse.read_chunked can enter an infinite loop because the Deflate decoder retains trailing bytes as unconsumed input after reaching end-of-stream and repeatedly decodes them without progress. The issue occurs when an untrusted server sends a chunked Deflate response whose decoded body exceeds a positive finite chunk size and whose encoded body has trailing bytes, specifically a response with Transfer-Encoding: chunked and Content-Encoding: deflate, content decoding enabled, and the positive finite amt=N streaming chunk size. The attack mechanism is that a malicious server returns a compressed chunked response with trailing bytes after the Deflate stream. The impact is excessive CPU usage and a request that does not complete, and network read timeouts do not interrupt the loop because no further socket read occurs. This issue is fixed in version 2.8.0.",
    "evidence": "osv:DEBIAN-CVE-2026-97688",
    "products": [
      {
        "name": {
          "value": "python-urllib3",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.8.0-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2.3.0-3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.0-1.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.5.0-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.6.3-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.6.3-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.7.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.7.0-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.7.0-3",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2026-97688",
      "aliases": [
        "DEBIAN-CVE-2026-97688"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.8.0-1"
                }
              ]
            }
          ],
          "package": {
            "name": "python-urllib3",
            "purl": "pkg:deb/debian/python-urllib3?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "versions": [
            "2.3.0-3",
            "2.5.0-1",
            "2.5.0-1.1",
            "2.5.0-2",
            "2.6.3-1",
            "2.6.3-2",
            "2.7.0-1",
            "2.7.0-2",
            "2.7.0-3"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-97688.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-14T10:00:39.740594775Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-97688"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2026-97688"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-97688",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 315376,
  "published_at": "2026-09-29T16:17:18.68+00:00"
}