CVE-2026-78663 affecting package flannel 0.24.2-32
The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
- Products
- flannel
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-78663
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 14:06 UTC · Revision 1
Source evidence
CVE-2026-78663 affecting package flannel 0.24.2-32
core-osv · Original sourcePublished 8 Oct 2026, 23:17 UTC
The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
osv:AZL-107384
flannel
Fixed versions: Not specified
Complete source record
{
"id": "25244753f7373114116a900dd8340f10e9a7adf1845493c8cb660f42b502a799",
"url": "https://osv.dev/vulnerability/AZL-107384",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2026-78663 affecting package flannel 0.24.2-32",
"summary": "The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.",
"evidence": "osv:AZL-107384",
"products": [
{
"name": {
"value": "flannel",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "AZL-107384",
"aliases": [
"AZL-107384"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"last_affected": "0.24.2-32"
}
]
}
],
"package": {
"name": "flannel",
"purl": "pkg:rpm/azure-linux/flannel",
"ecosystem": "Azure Linux:3"
},
"database_specific": {
"source": "https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-107384.json"
}
}
],
"modified": "2026-10-15T05:37:09Z",
"provider": "osv",
"upstream": [
"CVE-2026-78663"
],
"references": [
"https://nvd.nist.gov/vuln/detail/CVE-2026-78663"
]
},
"related_cves": [
{
"value": "CVE-2026-78663",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 321479,
"published_at": "2026-10-08T23:17:03+00:00"
}