CVE-2026-71218 (GCVE-0-2026-71218)
Vulnerability from cvelistv5 – Published: 2026-08-11 08:51 – Updated: 2026-08-11 13:00
VLAI
EPSS
VEX
Title
Iperf3: unbounded peer-controlled allocation in iperf3 json_read() allows unauthenticated remote memory exhaustion
Summary
A flaw was found in iperf3. A remote unauthenticated attacker can exploit a vulnerability in the `JSON_read()` function, which accepts a peer-controlled message length and allocates memory without an upper bound. This allows the attacker to trigger excessive memory consumption, leading to a Denial of Service (DoS) through memory exhaustion, severe slowdown, or termination of the iperf3 service.
Severity
5.3 (Medium)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-11 12:54 UTC
CWE
- CWE-789 - Memory Allocation with Excessive Size Value
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-71218 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2463003 | issue-trackingx_refsource_REDHAT |
| https://github.com/esnet/iperf/commit/0128d0357b7… |
Impacted products
4 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 |
cpe:/o:redhat:enterprise_linux:10
|
||
| Red Hat | Red Hat Enterprise Linux 7 |
cpe:/o:redhat:enterprise_linux:7
|
||
| Red Hat | Red Hat Enterprise Linux 8 |
cpe:/o:redhat:enterprise_linux:8
|
||
| Red Hat | Red Hat Enterprise Linux 9 |
cpe:/o:redhat:enterprise_linux:9
|
Date Public
2026-08-11 08:13
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-71218",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-11T12:54:34.803644Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-11T13:00:19.528Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
}
],
"credits": [
{
"lang": "en",
"value": "This issue was discovered by Found by AISLE in partnership with Red Hat."
}
],
"datePublic": "2026-08-11T08:13:07.439Z",
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in iperf3. A remote unauthenticated attacker can exploit a vulnerability in the `JSON_read()` function, which accepts a peer-controlled message length and allocates memory without an upper bound. This allows the attacker to trigger excessive memory consumption, leading to a Denial of Service (DoS) through memory exhaustion, severe slowdown, or termination of the iperf3 service."
}
],
"metrics": [
{
"other": {
"content": {
"namespace": "https://access.redhat.com/security/updates/classification/",
"value": "Moderate"
},
"type": "Red Hat severity rating"
}
},
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"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:L",
"version": "3.1"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-789",
"description": "Memory Allocation with Excessive Size Value",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-11T10:20:34.420Z",
"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"shortName": "redhat"
},
"references": [
{
"tags": [
"vdb-entry",
"x_refsource_REDHAT"
],
"url": "https://access.redhat.com/security/cve/CVE-2026-71218"
},
{
"name": "RHBZ#2463003",
"tags": [
"issue-tracking",
"x_refsource_REDHAT"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2463003"
},
{
"url": "https://github.com/esnet/iperf/commit/0128d0357b7e8916fe39e980e455729bc0e5fd4e"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-04-26T20:37:37.000Z",
"value": "Reported to Red Hat."
},
{
"lang": "en",
"time": "2026-08-11T08:13:07.439Z",
"value": "Made public."
}
],
"title": "Iperf3: unbounded peer-controlled allocation in iperf3 json_read() allows unauthenticated remote memory exhaustion",
"workarounds": [
{
"lang": "en",
"value": "To mitigate this issue, restrict network access to the `iperf3` control port, ensuring it is only reachable by trusted clients. This can be achieved by configuring firewall rules to limit inbound connections to the `iperf3` service. Additionally, consider running the `iperf3` service within environments that enforce process or container memory limits to further contain potential resource exhaustion. Note that authentication alone is insufficient as the memory allocation occurs before authentication checks."
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
},
"x_redhatCweChain": "CWE-789: Memory Allocation with Excessive Size Value"
}
},
"cveMetadata": {
"assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"assignerShortName": "redhat",
"cveId": "CVE-2026-71218",
"datePublished": "2026-08-11T08:51:24.805Z",
"dateReserved": "2026-08-05T08:41:54.899Z",
"dateUpdated": "2026-08-11T13:00:19.528Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-71218",
"date": "2026-10-16",
"epss": "0.00666",
"percentile": "0.50809"
},
"microsoft_vex": {
"current_release_date": "2026-08-23T14:56:07.000Z",
"cve": "CVE-2026-71218",
"id": "msrc_CVE-2026-71218",
"initial_release_date": "2026-08-14T19:01:42.000Z",
"product_status:fixed": "1",
"product_status:known_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "Iperf3: unbounded peer-controlled allocation in iperf3 json_read() allows unauthenticated remote memory exhaustion",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-71218.json",
"version": "2"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
}
],
"source": "secalert@redhat.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in iperf3. A remote unauthenticated attacker can exploit a vulnerability in the `JSON_read()` function, which accepts a peer-controlled message length and allocates memory without an upper bound. This allows the attacker to trigger excessive memory consumption, leading to a Denial of Service (DoS) through memory exhaustion, severe slowdown, or termination of the iperf3 service."
}
],
"id": "CVE-2026-71218",
"lastModified": "2026-08-14T19:07:46.080",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"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:L",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 1.4,
"source": "secalert@redhat.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-71218",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-11T12:54:34.803644Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-11T09:17:14.200",
"references": [
{
"source": "secalert@redhat.com",
"url": "https://access.redhat.com/security/cve/CVE-2026-71218"
},
{
"source": "secalert@redhat.com",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2463003"
},
{
"source": "secalert@redhat.com",
"url": "https://github.com/esnet/iperf/commit/0128d0357b7e8916fe39e980e455729bc0e5fd4e"
}
],
"sourceIdentifier": "secalert@redhat.com",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-789"
}
],
"source": "secalert@redhat.com",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-08-11T10:20:33+00:00",
"cve": "CVE-2026-71218",
"id": "CVE-2026-71218",
"initial_release_date": "2026-08-11T08:13:07.439000+00:00",
"product_status:known_affected": "9",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "iperf3: Unbounded peer-controlled allocation in iperf3 JSON_read() allows unauthenticated remote memory exhaustion",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-71218.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-71218",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-11T12:54:34.803644Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-11T13:00:14.163Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"defaultStatus": "affected",
"packageName": "iperf3",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
}
],
"credits": [
{
"lang": "en",
"value": "This issue was discovered by Found by AISLE in partnership with Red Hat."
}
],
"datePublic": "2026-08-11T08:13:07.439Z",
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in iperf3. A remote unauthenticated attacker can exploit a vulnerability in the `JSON_read()` function, which accepts a peer-controlled message length and allocates memory without an upper bound. This allows the attacker to trigger excessive memory consumption, leading to a Denial of Service (DoS) through memory exhaustion, severe slowdown, or termination of the iperf3 service."
}
],
"metrics": [
{
"other": {
"content": {
"namespace": "https://access.redhat.com/security/updates/classification/",
"value": "Moderate"
},
"type": "Red Hat severity rating"
}
},
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"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:L",
"version": "3.1"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-789",
"description": "Memory Allocation with Excessive Size Value",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-11T10:20:34.420Z",
"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"shortName": "redhat"
},
"references": [
{
"tags": [
"vdb-entry",
"x_refsource_REDHAT"
],
"url": "https://access.redhat.com/security/cve/CVE-2026-71218"
},
{
"name": "RHBZ#2463003",
"tags": [
"issue-tracking",
"x_refsource_REDHAT"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2463003"
},
{
"url": "https://github.com/esnet/iperf/commit/0128d0357b7e8916fe39e980e455729bc0e5fd4e"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-04-26T20:37:37.000Z",
"value": "Reported to Red Hat."
},
{
"lang": "en",
"time": "2026-08-11T08:13:07.439Z",
"value": "Made public."
}
],
"title": "Iperf3: unbounded peer-controlled allocation in iperf3 json_read() allows unauthenticated remote memory exhaustion",
"workarounds": [
{
"lang": "en",
"value": "To mitigate this issue, restrict network access to the `iperf3` control port, ensuring it is only reachable by trusted clients. This can be achieved by configuring firewall rules to limit inbound connections to the `iperf3` service. Additionally, consider running the `iperf3` service within environments that enforce process or container memory limits to further contain potential resource exhaustion. Note that authentication alone is insufficient as the memory allocation occurs before authentication checks."
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
},
"x_redhatCweChain": "CWE-789: Memory Allocation with Excessive Size Value"
}
},
"cveMetadata": {
"assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"assignerShortName": "redhat",
"cveId": "CVE-2026-71218",
"datePublished": "2026-08-11T08:51:24.805Z",
"dateReserved": "2026-08-05T08:41:54.899Z",
"dateUpdated": "2026-08-11T13:00:19.528Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.