High
Security advisory
A flaw was found in python. In algorithms with quadratic time complexity using non-binary bases, when using int("text"), a system could take 50ms to parse an int string with 100,000 digits and 5s for 1,000,000 digits (float, decimal, int.from_bytes(), and int() for binary bases 2, 4, 8, 16, and 32 are not affected). The highest threat from this vulnerability is to system availability.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-10735
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 10:40 UTC · Revision 1
Source evidence
A flaw was found in python. In algorithms with quadratic time complexity using non-binary bases, when using int("text"), a system could take 50ms to parse an int string with 100,000 digits and 5s for 1,000,000 digits (float, decimal, int.from_bytes(), and int() for binary bases 2, 4, 8, 16, and 32 are not affected). The highest threat from this vulnerability is to system availability.
osv:CVE-2020-10735
Complete source record
{
"id": "e328d742eac7c45b31b9b6c46672158db61a2887c30ecf91efc8e687b82affd0",
"url": "https://osv.dev/vulnerability/CVE-2020-10735",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-10735",
"summary": "A flaw was found in python. In algorithms with quadratic time complexity using non-binary bases, when using int(\"text\"), a system could take 50ms to parse an int string with 100,000 digits and 5s for 1,000,000 digits (float, decimal, int.from_bytes(), and int() for binary bases 2, 4, 8, 16, and 32 are not affected). The highest threat from this vulnerability is to system availability.",
"evidence": "osv:CVE-2020-10735",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2020-10735",
"aliases": [
"BIT-libpython-2020-10735",
"BIT-python-2020-10735",
"BIT-python-min-2020-10735",
"CVE-2020-10735",
"PSF-2022-4"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
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"repo": "https://github.com/python/cpython",
"type": "GIT",
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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{
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"range": [
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{
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{
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"range": [
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{
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{
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"range": [
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],
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},
{
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"range": [
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},
{
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],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
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"v3.11.0rc1"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-10735.json"
}
}
],
"modified": "2026-10-20T10:50:59.350891353Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-398330.html",
"https://cert-portal.siemens.com/productcert/html/ssa-806742.html",
"https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html",
"https://lists.debian.org/debian-lts-announce/2024/11/msg00024.html",
"https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2VCU6EVQDIXNCEDJUCTFIER2WVNNDTYZ/",
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"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4EWKR2SPX3JORLWCXFY3KN2U5B5CIUQQ/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6XL6E5A3I36TRR73VNBOXNIQP4AMZDFZ/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/76YE7AM37MRU76XJV4M27CWDAMUGNRYK/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HSRPVJZL6DJFWKYRHMNJB7VCEUCBKRF5/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IFGV7P2PYFBMK32OKHCAC2ZPJQV5AUDF/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NHC6IUU7CLRQ3QLPWUXLONSG3SXFTR47/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OKYE2DOI2X7WZXAWTQJZAXYIWM37HDCY/",
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"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OT5WQB7Z3CXOWVBD2AFAHYPA5ONYFFZ4/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PD7FTLJOIGMUSCDR3JAN6WRFHJEE4PH5/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SZYJSGLSCQOKXXFVJVJQAXLEOJBIWGEL/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TD7JDDKJXK6D26XAN3YRFNM2LAJHT5UO/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMWPRAAJS7I6U3U45V7GZVXWNSECI22M/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U4ZZV4CDFRMTPDBI7C5L43RFL3XLIGUY/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UBPDVCDIUCEBE7C4NAGNA2KQJYOTPBAZ/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V7ZUJDHK7KNG6SLIFXW7MNZ6O2PUJYK6/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WXF6MQ74HVIDDSR5AE2UDR24I6D4FEPC/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZEOAJWGGY55QU35UM2OVZATBW5MX2OZD/",
"https://access.redhat.com/security/cve/CVE-2020-10735",
"https://docs.google.com/document/d/1KjuF_aXlzPUxTK4BMgezGJ2Pn7uevfX7g0_mvgHlL7Y",
"https://bugzilla.redhat.com/show_bug.cgi?id=1834423",
"https://github.com/python/cpython/issues/95778"
],
"provider_metadata": {
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{
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"cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
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"source": "CPE_STRING"
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{
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{
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{
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}
},
"related_cves": [
{
"value": "CVE-2020-10735",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 382417,
"published_at": "2022-09-09T14:15:08.66+00:00"
}