ubuntu-cve-2026-69249
Vulnerability from osv_ubuntu
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.
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-cryptography",
"binary_version": "46.0.5-1ubuntu2.2"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "python-cryptography",
"purl": "pkg:deb/ubuntu/python-cryptography@46.0.5-1ubuntu2.2?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"43.0.0-1ubuntu1",
"46.0.1-1ubuntu2",
"46.0.5-1ubuntu1",
"46.0.5-1ubuntu2",
"46.0.5-1ubuntu2.2"
]
}
],
"aliases": [],
"details": "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.",
"id": "UBUNTU-CVE-2026-69249",
"modified": "2026-09-16T17:29:02Z",
"published": "2026-08-03T22:16:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-69249"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-69249"
},
{
"type": "REPORT",
"url": "https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww"
},
{
"type": "REPORT",
"url": "https://github.com/pyca/cryptography/pull/14960"
},
{
"type": "REPORT",
"url": "https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"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",
"type": "CVSS_V4"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-69249"
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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