CVE-2026-73550 (GCVE-0-2026-73550)
Vulnerability from cvelistv5
Published
2026-09-21 19:49
Modified
2026-09-28 20:37
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-401 - Missing Release of Memory after Effective Lifetime
Summary
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy copies every decoded HTTP/2 Host header value before discarding it when :authority is already present. The discarded value bypasses saveHeader, so its bytes and count are not charged against request header limits. An unauthenticated client can use HPACK indexing to submit many references to a large Host value across a bounded number of streams, forcing extreme header-copy allocation and causing the proxy to be out-of-memory killed. The relevant scope boundary is that the demonstrated amplification uses HTTP/2 HPACK and the duplicate Host discard behavior. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
References
| URL | Tags | ||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||||||||||||||||||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| envoyproxy | envoy |
Version: < 1.36.10 Version: >= 1.37.0, < 1.37.6 Version: >= 1.38.0, < 1.38.4 Version: >= 1.39.0, < 1.39.1 |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-73550",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-28T20:36:57.251407Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-09-28T20:37:02.865Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-qgf6-qvhw-4hvh"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "envoy",
"vendor": "envoyproxy",
"versions": [
{
"status": "affected",
"version": "\u003c 1.36.10"
},
{
"status": "affected",
"version": "\u003e= 1.37.0, \u003c 1.37.6"
},
{
"status": "affected",
"version": "\u003e= 1.38.0, \u003c 1.38.4"
},
{
"status": "affected",
"version": "\u003e= 1.39.0, \u003c 1.39.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy copies every decoded HTTP/2 Host header value before discarding it when :authority is already present. The discarded value bypasses saveHeader, so its bytes and count are not charged against request header limits. An unauthenticated client can use HPACK indexing to submit many references to a large Host value across a bounded number of streams, forcing extreme header-copy allocation and causing the proxy to be out-of-memory killed. The relevant scope boundary is that the demonstrated amplification uses HTTP/2 HPACK and the duplicate Host discard behavior. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1."
}
],
"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"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-401",
"description": "CWE-401: Missing Release of Memory after Effective Lifetime",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-21T19:49:28.641Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-qgf6-qvhw-4hvh",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-qgf6-qvhw-4hvh"
},
{
"name": "https://github.com/envoyproxy/envoy/commit/0910997f70e91d2d20c329bb507bfce44ce01f80",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/commit/0910997f70e91d2d20c329bb507bfce44ce01f80"
},
{
"name": "https://github.com/envoyproxy/envoy/commit/1fec994c868df008cdd4ae285aab58a196fd31f2",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/commit/1fec994c868df008cdd4ae285aab58a196fd31f2"
},
{
"name": "https://github.com/envoyproxy/envoy/commit/3fd0ffee7ac87adf3bc6e421656bb96310512300",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/commit/3fd0ffee7ac87adf3bc6e421656bb96310512300"
},
{
"name": "https://github.com/envoyproxy/envoy/commit/fc75d8e35b0d11acbae18b63a0bd96e32e84f61b",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/commit/fc75d8e35b0d11acbae18b63a0bd96e32e84f61b"
},
{
"name": "https://github.com/envoyproxy/envoy/releases/tag/v1.36.10",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.36.10"
},
{
"name": "https://github.com/envoyproxy/envoy/releases/tag/v1.37.6",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.37.6"
},
{
"name": "https://github.com/envoyproxy/envoy/releases/tag/v1.38.4",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.38.4"
},
{
"name": "https://github.com/envoyproxy/envoy/releases/tag/v1.39.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/envoyproxy/envoy/releases/tag/v1.39.1"
}
],
"source": {
"advisory": "GHSA-qgf6-qvhw-4hvh",
"discovery": "UNKNOWN"
},
"title": "Envoy: HTTP/2 Discarded Host Header 200 GB Header-Copy OOM in Envoy"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-73550",
"datePublished": "2026-09-21T19:49:28.641Z",
"dateReserved": "2026-08-12T20:53:46.379Z",
"dateUpdated": "2026-09-28T20:37:02.865Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-73550\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-09-28T20:36:57.251407Z\"}}}], \"references\": [{\"url\": \"https://github.com/envoyproxy/envoy/security/advisories/GHSA-qgf6-qvhw-4hvh\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-09-28T20:36:42.914Z\"}}], \"cna\": {\"title\": \"Envoy: HTTP/2 Discarded Host Header 200 GB Header-Copy OOM in Envoy\", \"source\": {\"advisory\": \"GHSA-qgf6-qvhw-4hvh\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"envoyproxy\", \"product\": \"envoy\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.36.10\"}, {\"status\": \"affected\", \"version\": \"\u003e= 1.37.0, \u003c 1.37.6\"}, {\"status\": \"affected\", \"version\": \"\u003e= 1.38.0, \u003c 1.38.4\"}, {\"status\": \"affected\", \"version\": \"\u003e= 1.39.0, \u003c 1.39.1\"}]}], \"references\": [{\"url\": \"https://github.com/envoyproxy/envoy/security/advisories/GHSA-qgf6-qvhw-4hvh\", \"name\": \"https://github.com/envoyproxy/envoy/security/advisories/GHSA-qgf6-qvhw-4hvh\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/commit/0910997f70e91d2d20c329bb507bfce44ce01f80\", \"name\": \"https://github.com/envoyproxy/envoy/commit/0910997f70e91d2d20c329bb507bfce44ce01f80\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/commit/1fec994c868df008cdd4ae285aab58a196fd31f2\", \"name\": \"https://github.com/envoyproxy/envoy/commit/1fec994c868df008cdd4ae285aab58a196fd31f2\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/commit/3fd0ffee7ac87adf3bc6e421656bb96310512300\", \"name\": \"https://github.com/envoyproxy/envoy/commit/3fd0ffee7ac87adf3bc6e421656bb96310512300\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/commit/fc75d8e35b0d11acbae18b63a0bd96e32e84f61b\", \"name\": \"https://github.com/envoyproxy/envoy/commit/fc75d8e35b0d11acbae18b63a0bd96e32e84f61b\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10\", \"name\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6\", \"name\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4\", \"name\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1\", \"name\": \"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy copies every decoded HTTP/2 Host header value before discarding it when :authority is already present. The discarded value bypasses saveHeader, so its bytes and count are not charged against request header limits. An unauthenticated client can use HPACK indexing to submit many references to a large Host value across a bounded number of streams, forcing extreme header-copy allocation and causing the proxy to be out-of-memory killed. The relevant scope boundary is that the demonstrated amplification uses HTTP/2 HPACK and the duplicate Host discard behavior. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-401\", \"description\": \"CWE-401: Missing Release of Memory after Effective Lifetime\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-09-21T19:49:28.641Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-73550\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-09-28T20:37:02.865Z\", \"dateReserved\": \"2026-08-12T20:53:46.379Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-09-21T19:49:28.641Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…