Medium
open-iscsi — security advisory
A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption.
- Products
- open-iscsi
- Affected versions
- 2.0.873+git0.3b4b4500-13ubuntu3, 2.0.873+git0.3b4b4500-14ubuntu1, 2.0.873+git0.3b4b4500-14ubuntu3, 2.0.873+git0.3b4b4500-14ubuntu3.1, 2.0.873+git0.3b4b4500-14ubuntu3.2, 2.0.873+git0.3b4b4500-14ubuntu3.3, 2.0.873+git0.3b4b4500-14ubuntu3.4, 2.0.873+git0.3b4b4500-14ubuntu3.5, 2.0.873+git0.3b4b4500-14ubuntu3.6, 2.0.873+git0.3b4b4500-14ubuntu3.7, 2.0.873+git0.3b4b4500-14ubuntu3.7+esm1, 2.0.873-3ubuntu13, 2.0.873-3ubuntu7, 2.0.873-3ubuntu8, 2.0.873-3ubuntu9, 2.0.874-4ubuntu3, 2.0.874-4ubuntu4, 2.0.874-4ubuntu5, 2.0.874-5ubuntu1, 2.0.874-5ubuntu2, 2.0.874-5ubuntu2.1, 2.0.874-5ubuntu2.10, 2.0.874-5ubuntu2.11, 2.0.874-5ubuntu2.11+esm1, 2.0.874-5ubuntu2.2, 2.0.874-5ubuntu2.3, 2.0.874-5ubuntu2.4, 2.0.874-5ubuntu2.6, 2.0.874-5ubuntu2.7, 2.0.874-5ubuntu2.9, 2.0.874-7.1ubuntu3, 2.0.874-7.1ubuntu5, 2.0.874-7.1ubuntu6, 2.0.874-7.1ubuntu6.1, 2.0.874-7.1ubuntu6.2, 2.0.874-7.1ubuntu6.3, 2.0.874-7.1ubuntu6.4, 2.0.874-7.1ubuntu6.5, 2.1.11-1ubuntu3, 2.1.11-3ubuntu1, 2.1.11-3ubuntu2, 2.1.11-3ubuntu3, 2.1.11-3ubuntu3.1, 2.1.11-5ubuntu1, 2.1.11-5ubuntu4, 2.1.11-5ubuntu5, 2.1.11-5ubuntu6, 2.1.4-0ubuntu1, 2.1.4-0ubuntu2, 2.1.4-0ubuntu3, 2.1.4-0ubuntu4, 2.1.5-1ubuntu1, 2.1.5-1ubuntu1.1, 2.1.5-1ubuntu1.3, 2.1.8-1ubuntu2, 2.1.9-3ubuntu1, 2.1.9-3ubuntu2, 2.1.9-3ubuntu3, 2.1.9-3ubuntu4, 2.1.9-3ubuntu5.1, 2.1.9-3ubuntu5.2, 2.1.9-3ubuntu5.3, 2.1.9-3ubuntu5.4, 2.1.9-3ubuntu5.5
- Fixed versions
- Not specified
- CVEs
- CVE-2026-18727
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:55 UTC · Revision 1
Source evidence
A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption.
osv:UBUNTU-CVE-2026-18727
open-iscsi
Fixed versions: Not specified
open-iscsi
Fixed versions: Not specified
open-iscsi
Fixed versions: Not specified
open-iscsi
Fixed versions: Not specified
open-iscsi
Fixed versions: Not specified
open-iscsi
Fixed versions: Not specified
open-iscsi
Fixed versions: Not specified
open-iscsi
Fixed versions: Not specified
Complete source record
{
"id": "b2cf4d7776d4d0469b1e609280aeea1cf47762901fc01c7f228d5d138d70081f",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-18727",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-18727",
"summary": "A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption.",
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"binaries": [
{
"binary_name": "iscsiuio",
"binary_version": "2.1.11-3ubuntu3.1"
},
{
"binary_name": "libopeniscsiusr",
"binary_version": "2.1.11-3ubuntu3.1"
},
{
"binary_name": "open-iscsi",
"binary_version": "2.1.11-3ubuntu3.1"
}
]
}
}
],
"modified": "2026-10-17T12:59:54.247053204Z",
"provider": "osv",
"upstream": [
"CVE-2026-18727"
],
"references": [
"https://ubuntu.com/security/CVE-2026-18727",
"https://www.cve.org/CVERecord?id=CVE-2026-18727",
"https://access.redhat.com/security/cve/CVE-2026-18727",
"https://bugzilla.redhat.com/show_bug.cgi?id=2462956"
]
},
"related_cves": [
{
"value": "CVE-2026-18727",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 359917,
"published_at": "2026-08-12T22:17:00+00:00"
}