Medium
gobgp — security advisory
A weakness has been identified in osrg GoBGP up to 4.3.0. This impacts the function DecodeFromBytes of the file pkg/packet/bgp/bgp.go. Executing a manipulation of the argument data[1] can lead to off-by-one. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is said to be difficult. This patch is called 67c059413470df64bc20801c46f64058e88f800f. A patch should be applied to remediate this issue.
- Products
- gobgp
- Affected versions
- 1.15-1, 1.29-1, 1.29-1ubuntu0.1+esm1, 1.29-1ubuntu0.1+esm2, 1.33-1, 2.11.0-1, 2.12.0-1, 2.12.0-1ubuntu0.1~esm1, 2.12.0-1ubuntu0.1~esm2, 2.12.0-1ubuntu0.1~esm3, 2.25.0-2, 2.25.0-3, 2.25.0-3build1, 2.25.0-3ubuntu0.1, 2.25.0-3ubuntu0.1+esm1, 2.25.0-3ubuntu0.1+esm2, 2.25.0-3ubuntu0.1+esm3, 2.25.0-3ubuntu0.1+esm4, 3.16.0-1build1, 3.19.0-1, 3.21.0-1, 3.23.0-1, 3.23.0-1ubuntu0.1, 3.23.0-1ubuntu0.2, 3.23.0-1ubuntu0.2+esm1, 3.23.0-1ubuntu0.3, 3.23.0-1ubuntu0.3+esm1, 3.23.0-1ubuntu0.3+esm2, 3.23.0-1ubuntu0.3+esm3, 3.23.0-1ubuntu0.3+esm4, 3.35.0-1, 3.36.0-2, 3.36.0-2build1, 3.36.0-2ubuntu0.1~esm1, 4.8.0-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-5123
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:27 UTC · Revision 1
Source evidence
A weakness has been identified in osrg GoBGP up to 4.3.0. This impacts the function DecodeFromBytes of the file pkg/packet/bgp/bgp.go. Executing a manipulation of the argument data[1] can lead to off-by-one. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is said to be difficult. This patch is called 67c059413470df64bc20801c46f64058e88f800f. A patch should be applied to remediate this issue.
osv:UBUNTU-CVE-2026-5123
gobgp
Fixed versions: Not specified
gobgp
Fixed versions: Not specified
gobgp
Fixed versions: Not specified
gobgp
Fixed versions: Not specified
gobgp
Fixed versions: Not specified
gobgp
Fixed versions: Not specified
gobgp
Fixed versions: Not specified
Complete source record
{
"id": "8f9d114a83c97f7ba51f61744c66c7ce10ecc06f0c17abfb6124fbbed631c507",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-5123",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-5123",
"summary": "A weakness has been identified in osrg GoBGP up to 4.3.0. This impacts the function DecodeFromBytes of the file pkg/packet/bgp/bgp.go. Executing a manipulation of the argument data[1] can lead to off-by-one. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is said to be difficult. This patch is called 67c059413470df64bc20801c46f64058e88f800f. A patch should be applied to remediate this issue.",
"evidence": "osv:UBUNTU-CVE-2026-5123",
"products": [
{
"name": {
"value": "gobgp",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.15-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.29-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.29-1ubuntu0.1+esm1",
"evidence": "/affected/0/versions"
},
{
"value": "1.29-1ubuntu0.1+esm2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "gobgp",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.33-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.11.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.12.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.12.0-1ubuntu0.1~esm1",
"evidence": "/affected/1/versions"
},
{
"value": "2.12.0-1ubuntu0.1~esm2",
"evidence": "/affected/1/versions"
},
{
"value": "2.12.0-1ubuntu0.1~esm3",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "gobgp",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.25.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.25.0-3",
"evidence": "/affected/2/versions"
},
{
"value": "2.25.0-3build1",
"evidence": "/affected/2/versions"
},
{
"value": "2.25.0-3ubuntu0.1",
"evidence": "/affected/2/versions"
},
{
"value": "2.25.0-3ubuntu0.1+esm1",
"evidence": "/affected/2/versions"
},
{
"value": "2.25.0-3ubuntu0.1+esm2",
"evidence": "/affected/2/versions"
},
{
"value": "2.25.0-3ubuntu0.1+esm3",
"evidence": "/affected/2/versions"
},
{
"value": "2.25.0-3ubuntu0.1+esm4",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "gobgp",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.16.0-1build1",
"evidence": "/affected/3/versions"
},
{
"value": "3.19.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "3.21.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.1",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.2",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.2+esm1",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.3",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.3+esm1",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.3+esm2",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.3+esm3",
"evidence": "/affected/3/versions"
},
{
"value": "3.23.0-1ubuntu0.3+esm4",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "gobgp",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.35.0-1",
"evidence": "/affected/4/versions"
},
{
"value": "3.36.0-2",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "gobgp",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.36.0-2build1",
"evidence": "/affected/5/versions"
},
{
"value": "4.8.0-1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "gobgp",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.36.0-2",
"evidence": "/affected/6/versions"
},
{
"value": "3.36.0-2build1",
"evidence": "/affected/6/versions"
},
{
"value": "3.36.0-2ubuntu0.1~esm1",
"evidence": "/affected/6/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-5123",
"aliases": [
"UBUNTU-CVE-2026-5123"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "gobgp",
"purl": "pkg:deb/ubuntu/gobgp?arch=source&distro=esm-apps%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"1.15-1",
"1.29-1",
"1.29-1ubuntu0.1+esm1",
"1.29-1ubuntu0.1+esm2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "gobgpd",
"binary_version": "1.29-1ubuntu0.1+esm2"
},
{
"binary_name": "golang-github-osrg-gobgp-dev",
"binary_version": "1.29-1ubuntu0.1+esm2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "gobgp",
"purl": "pkg:deb/ubuntu/gobgp?arch=source&distro=esm-apps%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"1.33-1",
"2.11.0-1",
"2.12.0-1",
"2.12.0-1ubuntu0.1~esm1",
"2.12.0-1ubuntu0.1~esm2",
"2.12.0-1ubuntu0.1~esm3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "gobgpd",
"binary_version": "2.12.0-1ubuntu0.1~esm3"
},
{
"binary_name": "golang-github-osrg-gobgp-dev",
"binary_version": "2.12.0-1ubuntu0.1~esm3"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "gobgp",
"purl": "pkg:deb/ubuntu/gobgp?arch=source&distro=esm-apps%2Fjammy",
"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"versions": [
"2.25.0-2",
"2.25.0-3",
"2.25.0-3build1",
"2.25.0-3ubuntu0.1",
"2.25.0-3ubuntu0.1+esm1",
"2.25.0-3ubuntu0.1+esm2",
"2.25.0-3ubuntu0.1+esm3",
"2.25.0-3ubuntu0.1+esm4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "gobgpd",
"binary_version": "2.25.0-3ubuntu0.1+esm4"
},
{
"binary_name": "golang-github-osrg-gobgp-dev",
"binary_version": "2.25.0-3ubuntu0.1+esm4"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "gobgp",
"purl": "pkg:deb/ubuntu/gobgp?arch=source&distro=esm-apps%2Fnoble",
"ecosystem": "Ubuntu:Pro:24.04:LTS"
},
"versions": [
"3.16.0-1build1",
"3.19.0-1",
"3.21.0-1",
"3.23.0-1",
"3.23.0-1ubuntu0.1",
"3.23.0-1ubuntu0.2",
"3.23.0-1ubuntu0.2+esm1",
"3.23.0-1ubuntu0.3",
"3.23.0-1ubuntu0.3+esm1",
"3.23.0-1ubuntu0.3+esm2",
"3.23.0-1ubuntu0.3+esm3",
"3.23.0-1ubuntu0.3+esm4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "gobgpd",
"binary_version": "3.23.0-1ubuntu0.3+esm4"
},
{
"binary_name": "golang-github-osrg-gobgp-dev",
"binary_version": "3.23.0-1ubuntu0.3+esm4"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
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}
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}
],
"package": {
"name": "gobgp",
"purl": "pkg:deb/ubuntu/gobgp?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"3.35.0-1",
"3.36.0-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "gobgpd",
"binary_version": "3.36.0-2"
},
{
"binary_name": "golang-github-osrg-gobgp-dev",
"binary_version": "3.36.0-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "gobgp",
"purl": "pkg:deb/ubuntu/gobgp?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"3.36.0-2build1",
"4.8.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "gobgpd",
"binary_version": "4.8.0-1"
},
{
"binary_name": "golang-github-osrg-gobgp-dev",
"binary_version": "4.8.0-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "gobgp",
"purl": "pkg:deb/ubuntu/gobgp?arch=source&distro=esm-apps%2Fresolute",
"ecosystem": "Ubuntu:Pro:26.04:LTS"
},
"versions": [
"3.36.0-2",
"3.36.0-2build1",
"3.36.0-2ubuntu0.1~esm1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-5123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "gobgpd",
"binary_version": "3.36.0-2ubuntu0.1~esm1"
},
{
"binary_name": "golang-github-osrg-gobgp-dev",
"binary_version": "3.36.0-2ubuntu0.1~esm1"
}
]
}
}
],
"modified": "2026-10-17T12:58:33.704884052Z",
"provider": "osv",
"upstream": [
"CVE-2026-5123"
],
"references": [
"https://ubuntu.com/security/CVE-2026-5123",
"https://www.cve.org/CVERecord?id=CVE-2026-5123",
"https://github.com/osrg/gobgp/pull/3342"
]
},
"related_cves": [
{
"value": "CVE-2026-5123",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 358774,
"published_at": "2026-03-30T16:16:00+00:00"
}