CVE-2026-110353
High 7.5
HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage.
Assigner
mitre
mitre
Published
2026-10-22
2026-10-22
Updated
2026-10-22
2026-10-22
Reserved
2026-10-13
2026-10-13
Scores
| Source | CVSS | Score | Severity | Vector |
|---|---|---|---|---|
| mitre | 3.1 | 7.5 | High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Weaknesses
Affected
| Vendor | Product | Versions |
|---|---|---|
| HAProxy | HAProxy | 3.2.0 to < 3.2.26 (affected) 3.3.0 to < 3.3.17 (affected) 3.4.0 to < 3.4.6 (affected) 3.5-dev to < 3.5-dev9 (affected) others: unaffected |
| HAProxy | HAProxy Enterprise Edition | 3.2.0r1 to < 3.2r1-378.1259 (affected) 3.3.0r1 to < 3.3r1-377.1005 (affected) others: unaffected |
| HAProxy | Kubernetes Ingress Controller | 3.2.0 to < 3.2.17 (affected)
others: unaffected |
| Haproxy | Kubernetes Ingress Controller Enterprise | 3.2.0 to < 3.2.17-ee1 (affected) 3.0 to < 3.0.16-ee17 (affected) 1.11 to < 1.11.14-ee11 (affected) others: unaffected |
References
- https://git.haproxy.org/?p=haproxy.git;a=commit;h=cec63e95f62a7412484f1134f5aa227e5b7e1466 vendor-advisory
Full CVE JSON record (5.2)
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"modules": [
"mux-h2"
],
"product": "HAProxy",
"programFiles": [
"src/mux_h2.c"
],
"programRoutines": [
{
"name": "h2c_handle_ping"
}
],
"repo": "https://git.haproxy.org/git/haproxy.git/",
"vendor": "HAProxy",
"versions": [
{
"lessThan": "3.2.26",
"status": "affected",
"version": "3.2.0",
"versionType": "custom"
},
{
"lessThan": "3.3.17",
"status": "affected",
"version": "3.3.0",
"versionType": "custom"
},
{
"lessThan": "3.4.6",
"status": "affected",
"version": "3.4.0",
"versionType": "custom"
},
{
"lessThan": "3.5-dev9",
"status": "affected",
"version": "3.5-dev",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unaffected",
"product": "HAProxy Enterprise Edition",
"vendor": "HAProxy",
"versions": [
{
"lessThan": "3.2r1-378.1259",
"status": "affected",
"version": "3.2.0r1",
"versionType": "custom"
},
{
"lessThan": "3.3r1-377.1005",
"status": "affected",
"version": "3.3.0r1",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unaffected",
"product": "Kubernetes Ingress Controller",
"vendor": "HAProxy",
"versions": [
{
"lessThan": "3.2.17",
"status": "affected",
"version": "3.2.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unaffected",
"product": "Kubernetes Ingress Controller Enterprise",
"vendor": "Haproxy",
"versions": [
{
"lessThan": "3.2.17-ee1",
"status": "affected",
"version": "3.2.0",
"versionType": "custom"
},
{
"lessThan": "3.0.16-ee17",
"status": "affected",
"version": "3.0",
"versionType": "custom"
},
{
"lessThan": "1.11.14-ee11",
"status": "affected",
"version": "1.11",
"versionType": "custom"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-252",
"description": "CWE-252 Unchecked Return Value",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-22T02:53:33.198Z",
"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
"shortName": "mitre"
},
"references": [
{
"tags": [
"vendor-advisory"
],
"url": "https://git.haproxy.org/?p=haproxy.git;a=commit;h=cec63e95f62a7412484f1134f5aa227e5b7e1466"
}
],
"x_generator": {
"engine": "CVE-Request-form 0.0.1"
}
}
},
"cveMetadata": {
"assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
"assignerShortName": "mitre",
"cveId": "CVE-2026-110353",
"datePublished": "2026-10-22T02:53:33.198Z",
"dateReserved": "2026-10-13T23:18:04.062Z",
"dateUpdated": "2026-10-22T02:53:33.198Z",
"state": "PUBLISHED"
},
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"dataVersion": "5.2"
}