openssl — security advisory
Issue summary: The QUIC stream reassembly algorithm performance deteriorates progressively as packets are arriving out of order. The worst case has a quadratic complexity proportional to the number of stream frames kept in the buffer for the received stream data. Impact summary: A remote QUIC peer that completes the handshake can create a connection-scoped CPU pressure and potentially a Denial of Service using compliant STREAM frames inside the advertised receive window, with low attacker bandwidth. CWE: CWE-407: Inefficient Algorithmic Complexity Description: OpenSSL manages received QUIC stream fragments using a doubly-linked list. While it optimizes for append operations (at the end of the list), it falls back to a head-to-tail linear search for any fragment that does not immediately follow the current `tail`. By manipulating the sequence of offsets, an attacker can force the server to perform O(n^2) operations, consuming excessive CPU time for the QUIC process. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.
- Products
- openssl
- Affected versions
- 3.5.1-1, 3.5.1-1+deb13u1, 3.5.2-1, 3.5.3-1, 3.5.4-1, 3.5.4-1~deb13u1, 3.5.4-1~deb13u2, 3.5.5-1, 3.5.5-1~deb13u1, 3.5.5-1~deb13u2, 3.5.6-1~deb13u1, 3.5.6-1~deb13u2, 3.5.7-1~deb13u1, 3.5.7-1~deb13u2, 3.5.7-1~deb13u3, 3.6.0-1, 3.6.0-2, 3.6.0~~alpha1-1, 3.6.0~~beta1-1, 3.6.1-1, 3.6.1-2, 3.6.1-3, 3.6.2-1, 3.6.3-1, 3.6.4-1
- Fixed versions
- 3.5.7-1~deb13u3, 3.6.5-1
- CVEs
- CVE-2026-42772
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 10:34 UTC · Revision 1
Source evidence
Issue summary: The QUIC stream reassembly algorithm performance deteriorates progressively as packets are arriving out of order. The worst case has a quadratic complexity proportional to the number of stream frames kept in the buffer for the received stream data. Impact summary: A remote QUIC peer that completes the handshake can create a connection-scoped CPU pressure and potentially a Denial of Service using compliant STREAM frames inside the advertised receive window, with low attacker bandwidth. CWE: CWE-407: Inefficient Algorithmic Complexity Description: OpenSSL manages received QUIC stream fragments using a doubly-linked list. While it optimizes for append operations (at the end of the list), it falls back to a head-to-tail linear search for any fragment that does not immediately follow the current `tail`. By manipulating the sequence of offsets, an attacker can force the server to perform O(n^2) operations, consuming excessive CPU time for the QUIC process. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.
osv:DEBIAN-CVE-2026-42772
openssl
Fixed versions: 3.5.7-1~deb13u3
openssl
Fixed versions: 3.6.5-1
Complete source record
{
"id": "4be215b48582348f791878dce540262b378fe7ee9defb7c2ba7dde77d435ca81",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-42772",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-42772",
"summary": "Issue summary: The QUIC stream reassembly algorithm performance deteriorates progressively as packets are arriving out of order. The worst case has a quadratic complexity proportional to the number of stream frames kept in the buffer for the received stream data. Impact summary: A remote QUIC peer that completes the handshake can create a connection-scoped CPU pressure and potentially a Denial of Service using compliant STREAM frames inside the advertised receive window, with low attacker bandwidth. CWE: CWE-407: Inefficient Algorithmic Complexity Description: OpenSSL manages received QUIC stream fragments using a doubly-linked list. While it optimizes for append operations (at the end of the list), it falls back to a head-to-tail linear search for any fragment that does not immediately follow the current `tail`. By manipulating the sequence of offsets, an attacker can force the server to perform O(n^2) operations, consuming excessive CPU time for the QUIC process. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.",
"evidence": "osv:DEBIAN-CVE-2026-42772",
"products": [
{
"name": {
"value": "openssl",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
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"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "3.5.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.1-1+deb13u1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.4-1",
"evidence": "/affected/0/versions"
},
{
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"evidence": "/affected/0/versions"
},
{
"value": "3.5.4-1~deb13u2",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.5-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.5-1~deb13u1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.5-1~deb13u2",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.6-1~deb13u1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.6-1~deb13u2",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.7-1~deb13u1",
"evidence": "/affected/0/versions"
},
{
"value": "3.5.7-1~deb13u2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "openssl",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.6.5-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "3.5.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.4-1~deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.4-1~deb13u2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.5-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.5-1~deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.5-1~deb13u2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.6-1~deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.6-1~deb13u2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.7-1~deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.7-1~deb13u2",
"evidence": "/affected/1/versions"
},
{
"value": "3.5.7-1~deb13u3",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.0~~alpha1-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.0~~beta1-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.1-2",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.1-3",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "3.6.4-1",
"evidence": "/affected/1/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2026-42772",
"aliases": [
"DEBIAN-CVE-2026-42772"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.5.7-1~deb13u3"
}
]
}
],
"package": {
"name": "openssl",
"purl": "pkg:deb/debian/openssl?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"3.5.1-1",
"3.5.1-1+deb13u1",
"3.5.2-1",
"3.5.3-1",
"3.5.4-1",
"3.5.4-1~deb13u1",
"3.5.4-1~deb13u2",
"3.5.5-1",
"3.5.5-1~deb13u1",
"3.5.5-1~deb13u2",
"3.5.6-1~deb13u1",
"3.5.6-1~deb13u2",
"3.5.7-1~deb13u1",
"3.5.7-1~deb13u2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42772.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.6.5-1"
}
]
}
],
"package": {
"name": "openssl",
"purl": "pkg:deb/debian/openssl?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"3.5.1-1",
"3.5.2-1",
"3.5.3-1",
"3.5.4-1",
"3.5.4-1~deb13u1",
"3.5.4-1~deb13u2",
"3.5.5-1",
"3.5.5-1~deb13u1",
"3.5.5-1~deb13u2",
"3.5.6-1~deb13u1",
"3.5.6-1~deb13u2",
"3.5.7-1~deb13u1",
"3.5.7-1~deb13u2",
"3.5.7-1~deb13u3",
"3.6.0-1",
"3.6.0-2",
"3.6.0~~alpha1-1",
"3.6.0~~beta1-1",
"3.6.1-1",
"3.6.1-2",
"3.6.1-3",
"3.6.2-1",
"3.6.3-1",
"3.6.4-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42772.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-08T23:00:10.470482816Z",
"provider": "osv",
"upstream": [
"CVE-2026-42772"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-42772"
]
},
"related_cves": [
{
"value": "CVE-2026-42772",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 107900,
"published_at": "2026-09-29T16:17:07.64+00:00"
}