HighFix available
python-cryptography — security advisory
python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.
- Products
- python-cryptography
- Affected versions
- 38.0.4-3, 38.0.4-3+deb12u1, 38.0.4-4, 41.0.7-1, 41.0.7-2, 41.0.7-3, 41.0.7-4, 41.0.7-5, 42.0.5-1, 42.0.5-2, 43.0.0-1, 43.0.0-2, 43.0.0-3, 43.0.0-3+deb13u1, 44.0.2-1, 44.0.2-2, 45.0.6-1, 45.0.6-1~exp1, 45.0.7-1, 46.0.1-1, 46.0.1-1~exp1, 46.0.5-1, 46.0.5-2, 46.0.6-1, 46.0.7-1, 47.0.0-1, 49.0.0-1, 49.0.0-1~exp1, 49.0.0-2, 50.0.2-1~exp1
- Fixed versions
- 49.0.0-1
- CVEs
- CVE-2026-69249
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 04:12 UTC · Revision 1
Source evidence
python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.
osv:DEBIAN-CVE-2026-69249
python-cryptography
Fixed versions: Not specified
python-cryptography
Fixed versions: Not specified
python-cryptography
Fixed versions: 49.0.0-1
Complete source record
{
"id": "d1a1b9bb052f27d9e264018796d3766ed9945e56ed7884736478ffa937a745cd",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-69249",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-69249",
"summary": "python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.",
"evidence": "osv:DEBIAN-CVE-2026-69249",
"products": [
{
"name": {
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{
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{
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{
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{
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{
"value": "41.0.7-3",
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{
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{
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{
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{
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{
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{
"value": "43.0.0-2",
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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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{
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{
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{
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"affected_versions": [
{
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{
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"evidence": "/affected/1/versions"
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{
"value": "44.0.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "44.0.2-2",
"evidence": "/affected/1/versions"
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{
"value": "45.0.6-1",
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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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{
"value": "46.0.7-1",
"evidence": "/affected/1/versions"
},
{
"value": "47.0.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "49.0.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "49.0.0-1~exp1",
"evidence": "/affected/1/versions"
},
{
"value": "49.0.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "50.0.2-1~exp1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "python-cryptography",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "49.0.0-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "43.0.0-3",
"evidence": "/affected/2/versions"
},
{
"value": "44.0.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "44.0.2-2",
"evidence": "/affected/2/versions"
},
{
"value": "45.0.6-1",
"evidence": "/affected/2/versions"
},
{
"value": "45.0.6-1~exp1",
"evidence": "/affected/2/versions"
},
{
"value": "45.0.7-1",
"evidence": "/affected/2/versions"
},
{
"value": "46.0.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "46.0.1-1~exp1",
"evidence": "/affected/2/versions"
},
{
"value": "46.0.5-1",
"evidence": "/affected/2/versions"
},
{
"value": "46.0.5-2",
"evidence": "/affected/2/versions"
},
{
"value": "46.0.6-1",
"evidence": "/affected/2/versions"
},
{
"value": "46.0.7-1",
"evidence": "/affected/2/versions"
},
{
"value": "47.0.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "49.0.0-1~exp1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-69249",
"aliases": [
"DEBIAN-CVE-2026-69249"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "python-cryptography",
"purl": "pkg:deb/debian/python-cryptography?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
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"38.0.4-3+deb12u1",
"38.0.4-4",
"41.0.7-1",
"41.0.7-2",
"41.0.7-3",
"41.0.7-4",
"41.0.7-5",
"42.0.5-1",
"42.0.5-2",
"43.0.0-1",
"43.0.0-2",
"43.0.0-3",
"44.0.2-1",
"44.0.2-2",
"45.0.6-1",
"45.0.6-1~exp1",
"45.0.7-1",
"46.0.1-1",
"46.0.1-1~exp1",
"46.0.5-1",
"46.0.5-2",
"46.0.6-1",
"46.0.7-1",
"47.0.0-1",
"49.0.0-1",
"49.0.0-1~exp1",
"49.0.0-2",
"50.0.2-1~exp1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-69249.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
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}
],
"package": {
"name": "python-cryptography",
"purl": "pkg:deb/debian/python-cryptography?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"43.0.0-3",
"43.0.0-3+deb13u1",
"44.0.2-1",
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"45.0.7-1",
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"46.0.7-1",
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"49.0.0-2",
"50.0.2-1~exp1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-69249.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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{
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},
{
"fixed": "49.0.0-1"
}
]
}
],
"package": {
"name": "python-cryptography",
"purl": "pkg:deb/debian/python-cryptography?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
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],
"database_specific": {
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},
"ecosystem_specific": {
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}
}
],
"modified": "2026-10-24T10:01:21.441890496Z",
"provider": "osv",
"upstream": [
"CVE-2026-69249"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-69249"
]
},
"related_cves": [
{
"value": "CVE-2026-69249",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 429079,
"published_at": "2026-08-03T22:16:52.72+00:00"
}