CVE-2026-7426 (GCVE-0-2026-7426)
Vulnerability from cvelistv5 – Published: 2026-04-29 18:53 – Updated: 2026-04-29 22:14
VLAI
EPSS
VEX
Title
Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP
Summary
Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.
To mitigate this issue, users should upgrade to the fixed version when available.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-29 19:33 UTC
CWE
- CWE-787 - Out-of-bounds Write
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/rel… | patch |
| https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/rel… | patch |
| https://aws.amazon.com/security/security-bulletin… | vendor-advisory |
| https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/sec… | third-party-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| AWS | FreeRTOS-Plus-TCP |
Affected:
4.0.0 , < 4.2.6
(semver)
Affected: 4.3.0 , < 4.4.1 (semver) Unaffected: 4.2.6 Unaffected: 4.4.1 |
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-7426",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-29T19:33:03.058186Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-29T19:33:24.116Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP",
"defaultStatus": "unaffected",
"product": "FreeRTOS-Plus-TCP",
"vendor": "AWS",
"versions": [
{
"lessThan": "4.2.6",
"status": "affected",
"version": "4.0.0",
"versionType": "semver"
},
{
"lessThan": "4.4.1",
"status": "affected",
"version": "4.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "4.2.6"
},
{
"status": "unaffected",
"version": "4.4.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eInsufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.\u003c/p\u003e\u003cp\u003eTo mitigate this issue, users should upgrade to the fixed version when available.\u003c/p\u003e"
}
],
"value": "Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.\n\n\n\nTo mitigate this issue, users should upgrade to the fixed version when available."
}
],
"impacts": [
{
"capecId": "CAPEC-153",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-153: Input Data Manipulation"
}
]
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "ADJACENT_NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.1,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
},
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "ADJACENT",
"baseScore": 6.1,
"baseSeverity": "MEDIUM",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-787",
"description": "CWE-787: Out-of-bounds Write",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-29T22:14:34.199Z",
"orgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"shortName": "AMZN"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1"
},
{
"tags": [
"patch"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://aws.amazon.com/security/security-bulletins/2026-023-aws/"
},
{
"tags": [
"third-party-advisory"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-97qg-4359-xm3x"
}
],
"source": {
"discovery": "UNKNOWN"
},
"title": "Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP",
"x_generator": {
"engine": "Vulnogram 1.0.1"
}
}
},
"cveMetadata": {
"assignerOrgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"assignerShortName": "AMZN",
"cveId": "CVE-2026-7426",
"datePublished": "2026-04-29T18:53:52.187Z",
"dateReserved": "2026-04-29T14:27:53.201Z",
"dateUpdated": "2026-04-29T22:14:34.199Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-7426",
"date": "2026-10-18",
"epss": "0.004",
"percentile": "0.32681"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"collectionURL": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP",
"defaultStatus": "unaffected",
"product": "FreeRTOS-Plus-TCP",
"vendor": "AWS",
"versions": [
{
"lessThan": "4.2.6",
"status": "affected",
"version": "4.0.0",
"versionType": "semver"
},
{
"lessThan": "4.4.1",
"status": "affected",
"version": "4.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "4.2.6"
},
{
"status": "unaffected",
"version": "4.4.1"
}
]
}
],
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*",
"matchCriteriaId": "DE7A5C38-9CEA-461B-9272-3B8BFC06BFEE",
"versionEndExcluding": "4.2.6",
"versionStartIncluding": "4.0.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*",
"matchCriteriaId": "375C7032-9CFB-480C-BFFA-029C985A82B7",
"versionEndExcluding": "4.4.1",
"versionStartIncluding": "4.3.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.\n\n\n\nTo mitigate this issue, users should upgrade to the fixed version when available."
}
],
"id": "CVE-2026-7426",
"lastModified": "2026-06-17T11:02:25.223",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "ADJACENT_NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.1,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 5.2,
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"type": "Secondary"
}
],
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "ADJACENT",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 6.1,
"baseSeverity": "MEDIUM",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-7426",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-29T19:33:03.058186Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-04-29T20:16:32.143",
"references": [
{
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"tags": [
"Vendor Advisory"
],
"url": "https://aws.amazon.com/security/security-bulletins/2026-023-aws/"
},
{
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"tags": [
"Release Notes"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6"
},
{
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"tags": [
"Release Notes"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1"
},
{
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"tags": [
"Patch",
"Vendor Advisory"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-97qg-4359-xm3x"
}
],
"sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-787"
}
],
"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"current_release_date": "2026-06-05T19:39:40+00:00",
"cve": "CVE-2026-7426",
"id": "CVE-2026-7426",
"initial_release_date": "2026-01-01T00:00:00+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-7426.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-7426",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-29T19:33:03.058186Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-29T19:33:08.227Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP",
"defaultStatus": "unaffected",
"product": "FreeRTOS-Plus-TCP",
"vendor": "AWS",
"versions": [
{
"lessThan": "4.2.6",
"status": "affected",
"version": "4.0.0",
"versionType": "semver"
},
{
"lessThan": "4.4.1",
"status": "affected",
"version": "4.3.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "4.2.6"
},
{
"status": "unaffected",
"version": "4.4.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eInsufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.\u003c/p\u003e\u003cp\u003eTo mitigate this issue, users should upgrade to the fixed version when available.\u003c/p\u003e"
}
],
"value": "Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.\n\n\n\nTo mitigate this issue, users should upgrade to the fixed version when available."
}
],
"impacts": [
{
"capecId": "CAPEC-153",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-153: Input Data Manipulation"
}
]
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "ADJACENT_NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.1,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
},
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "ADJACENT",
"baseScore": 6.1,
"baseSeverity": "MEDIUM",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-787",
"description": "CWE-787: Out-of-bounds Write",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-29T22:14:34.199Z",
"orgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"shortName": "AMZN"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1"
},
{
"tags": [
"patch"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://aws.amazon.com/security/security-bulletins/2026-023-aws/"
},
{
"tags": [
"third-party-advisory"
],
"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-97qg-4359-xm3x"
}
],
"source": {
"discovery": "UNKNOWN"
},
"title": "Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP",
"x_generator": {
"engine": "Vulnogram 1.0.1"
}
}
},
"cveMetadata": {
"assignerOrgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
"assignerShortName": "AMZN",
"cveId": "CVE-2026-7426",
"datePublished": "2026-04-29T18:53:52.187Z",
"dateReserved": "2026-04-29T14:27:53.201Z",
"dateUpdated": "2026-04-29T22:14:34.199Z",
"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.