DEBIAN-CVE-2026-85999
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.
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/versions2.4-1Source reference:
/affected/0/versions2.4.1-1Source reference:
/affected/0/versions2.4.1-2Source reference:
/affected/0/versions2.5-1Source reference:
/affected/0/versions2.6-1Source reference:
/affected/0/versions2.7-1Source reference:
/affected/0/versions2.7-2Source reference:
/affected/0/versions2.8.1-1Source reference:
/affected/0/versions2.8.3-1Source reference:
/affected/0/versions2.8.4-1Source 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/versions2.7-2Source reference:
/affected/1/versions2.8.1-1Source reference:
/affected/1/versions2.8.3-1Source reference:
/affected/1/versions2.8.4-1Source 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/versions2.7-2Source reference:
/affected/2/versions2.8.1-1Source reference:
/affected/2/versions2.8.3-1Source reference:
/affected/2/versions2.8.4-1Source 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
- Added to Heist Feed
- Publisher date