Low
Super-linear CPU usage for unbounded input to csv.Sniffer.sniff()
Attacker-controlled CSV samples can trigger super-linear regular-expression work during dialect sniffing and consume significant CPU when applications pass unbounded input to csv.Sniffer.sniff().
Announced Source revision 1
Original source ↗CVE-2026-18503
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: cve:CVE-2026-18503
CPython
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- 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.
[
{
"repo": "https://github.com/python/cpython",
"vendor": "Python Software Foundation",
"modules": [
"csv"
],
"product": "CPython",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "3.10.21",
"versionType": "python"
},
{
"status": "affected",
"version": "3.11.0",
"lessThan": "3.11.16",
"versionType": "python"
},
{
"status": "affected",
"version": "3.12.0",
"lessThan": "3.12.14",
"versionType": "python"
},
{
"status": "affected",
"version": "3.13.0",
"lessThan": "3.13.15",
"versionType": "python"
},
{
"status": "affected",
"version": "3.14.0",
"lessThan": "3.14.7",
"versionType": "python"
},
{
"status": "affected",
"version": "3.15.0a1",
"lessThan": "3.15.0rc1",
"versionType": "python"
},
{
"status": "affected",
"version": "3.16.0a1",
"lessThan": "3.16.0",
"versionType": "python"
}
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-18503
Source reference:
/cveMetadata/cveId
Publisher severity
low
Source reference: /containers/cna/metrics
- Event
- #21320 · Revision 1
- Added to Heist Feed
- Publisher date