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DEBIAN-CVE-2026-85999

Type: advisorySource: OSV1 source record

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selector_iter in src/soupsieve/css_parser.py trims the raw selector with RE_WS_END, an end-anchored WSC whitespace-and-comment expression used with search(), so the regular expression engine retries a greedy scan at every starting offset. An attacker-controlled valid selector containing a long internal whitespace run, or a selector containing a long CSS comment run followed by another token, causes quadratic CPU work before tokenization. User-controlled selectors can reach the path through soupsieve.compile() and BeautifulSoup.select(), while applications using only hard-coded selectors are unaffected. This root cause is separate from the IDENTIFIER and VALUE backtracking vulnerability because the cost occurs in RE_WS_END.search during trimming rather than token matching. The resulting CPU consumption can hold the Python GIL, exhaust workers, and stall a service without causing memory corruption or code execution. The issue is fixed in version 2.9.

Announced Source revision 1
Original source ↗

DEBIAN-CVE-2026-85999

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-2026-85999

soupsieve

Source reference: /affected/0/package/name

Affected versions
2.3.2-1

Source reference: /affected/0/versions

2.4-1

Source reference: /affected/0/versions

2.4.1-1

Source reference: /affected/0/versions

2.4.1-2

Source reference: /affected/0/versions

2.5-1

Source reference: /affected/0/versions

2.6-1

Source reference: /affected/0/versions

2.7-1

Source reference: /affected/0/versions

2.7-2

Source reference: /affected/0/versions

2.8.1-1

Source reference: /affected/0/versions

2.8.3-1

Source reference: /affected/0/versions

2.8.4-1

Source reference: /affected/0/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

soupsieve

Source reference: /affected/1/package/name

Affected versions
2.7-1

Source reference: /affected/1/versions

2.7-2

Source reference: /affected/1/versions

2.8.1-1

Source reference: /affected/1/versions

2.8.3-1

Source reference: /affected/1/versions

2.8.4-1

Source reference: /affected/1/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

soupsieve

Source reference: /affected/2/package/name

Affected versions
2.7-1

Source reference: /affected/2/versions

2.7-2

Source reference: /affected/2/versions

2.8.1-1

Source reference: /affected/2/versions

2.8.3-1

Source reference: /affected/2/versions

2.8.4-1

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": "soupsieve",
      "purl": "pkg:deb/debian/soupsieve?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "2.3.2-1",
      "2.4-1",
      "2.4.1-1",
      "2.4.1-2",
      "2.5-1",
      "2.6-1",
      "2.7-1",
      "2.7-2",
      "2.8.1-1",
      "2.8.3-1",
      "2.8.4-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85999.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "soupsieve",
      "purl": "pkg:deb/debian/soupsieve?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "2.7-1",
      "2.7-2",
      "2.8.1-1",
      "2.8.3-1",
      "2.8.4-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85999.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "soupsieve",
      "purl": "pkg:deb/debian/soupsieve?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "2.7-1",
      "2.7-2",
      "2.8.1-1",
      "2.8.3-1",
      "2.8.4-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-85999.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#6078 · Revision 1
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Publisher date
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