UBUNTU-CVE-2026-29013 (CVE-2026-29013)
Vulnerability from osv_ubuntu – Published: 2026-04-17 22:16 – Updated: 2026-06-04 10:59 – Source website
VLAI
Details
libcoap contains out-of-bounds read vulnerabilities in OSCORE Appendix B.2 CBOR unwrap handling where get_byte_inc() in src/oscore/oscore_cbor.c relies solely on assert() for bounds checking, which is removed in release builds compiled with NDEBUG. Attackers can send crafted CoAP requests with malformed OSCORE options or responses during OSCORE negotiation to trigger out-of-bounds reads during CBOR parsing and potentially cause out-of-bounds reads through integer wraparound in allocation size computation.
Severity
9.8 (Critical)
N/A (UNKNOWN)
References
| URL | Type | |
|---|---|---|
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcoap-1-0",
"binary_version": "4.1.2-1"
},
{
"binary_name": "libcoap-1-0-bin",
"binary_version": "4.1.2-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:18.04:LTS",
"name": "libcoap",
"purl": "pkg:deb/ubuntu/libcoap@4.1.2-1?arch=source\u0026distro=bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.1.2-1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcoap2",
"binary_version": "4.2.1-1"
},
{
"binary_name": "libcoap2-bin",
"binary_version": "4.2.1-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:20.04:LTS",
"name": "libcoap2",
"purl": "pkg:deb/ubuntu/libcoap2@4.2.1-1?arch=source\u0026distro=focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.2.0-2",
"4.2.1-1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcoap2",
"binary_version": "4.2.1-1build1"
},
{
"binary_name": "libcoap2-bin",
"binary_version": "4.2.1-1build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "libcoap2",
"purl": "pkg:deb/ubuntu/libcoap2@4.2.1-1build1?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.2.1-1",
"4.2.1-1build1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcoap3",
"binary_version": "4.3.0-2build1"
},
{
"binary_name": "libcoap3-bin",
"binary_version": "4.3.0-2build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "libcoap3",
"purl": "pkg:deb/ubuntu/libcoap3@4.3.0-2build1?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.3.0-2",
"4.3.0-2build1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcoap3-bin",
"binary_version": "4.3.4-1.1build4"
},
{
"binary_name": "libcoap3t64",
"binary_version": "4.3.4-1.1build4"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "libcoap3",
"purl": "pkg:deb/ubuntu/libcoap3@4.3.4-1.1build4?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.3.1-2",
"4.3.3-1",
"4.3.4-1",
"4.3.4-1.1build2",
"4.3.4-1.1build3",
"4.3.4-1.1build4"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcoap3-bin",
"binary_version": "4.3.4-1.1build4"
},
{
"binary_name": "libcoap3t64",
"binary_version": "4.3.4-1.1build4"
}
]
},
"package": {
"ecosystem": "Ubuntu:25.10",
"name": "libcoap3",
"purl": "pkg:deb/ubuntu/libcoap3@4.3.4-1.1build4?arch=source\u0026distro=questing"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.3.4-1.1build4"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcoap3-bin",
"binary_version": "4.3.5-2"
},
{
"binary_name": "libcoap3t64",
"binary_version": "4.3.5-2"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "libcoap3",
"purl": "pkg:deb/ubuntu/libcoap3@4.3.5-2?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.3.4-1.1build4",
"4.3.5-1",
"4.3.5-2"
]
}
],
"aliases": [],
"details": "libcoap contains out-of-bounds read vulnerabilities in OSCORE Appendix B.2 CBOR unwrap handling where get_byte_inc() in src/oscore/oscore_cbor.c relies solely on assert() for bounds checking, which is removed in release builds compiled with NDEBUG. Attackers can send crafted CoAP requests with malformed OSCORE options or responses during OSCORE negotiation to trigger out-of-bounds reads during CBOR parsing and potentially cause out-of-bounds reads through integer wraparound in allocation size computation.",
"id": "UBUNTU-CVE-2026-29013",
"modified": "2026-06-04T10:59:31Z",
"published": "2026-04-17T22:16:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-29013"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-29013"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
},
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-29013"
]
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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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.
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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.
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Related by attack behaviour
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