CVE-2026-18728
Open-iscsi: open-iscsi: integer underflow in iscsiuio ipv4 dhcp parsing
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
6.5
Open-iscsi: open-iscsi: integer underflow in iscsiuio ipv4 dhcp parsing
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
- Record
CVE-2026-18728- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-191
- Updated
- 2026-11-05
EUVDEUVD-2026-57715
6.5
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
- Record
EUVD-2026-57715- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-05
GitHub AdvisoriesGHSA-v5q9-q65g-v5rv
6.5
A flaw was found in open-iscsi. An integer underflow vulnerability in the `iscsiuio` component,...
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
- Record
GHSA-v5q9-q65g-v5rv- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-191
- Updated
- 2026-11-02
NVD
6.5
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
- Record
CVE-2026-18728- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-191
- Updated
- 2026-11-05
OSVDEBIAN-CVE-2026-18728
6.5
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
- Record
DEBIAN-CVE-2026-18728- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVOESA-2026-3511
7.6
open-iscsi security update
The Open-iSCSI project is a high-performance, transport independent, multi-platform implementation of RFC3720 iSCSI.
Security Fix(es):
A stack buffer overflow vulnerability exists in the idbm_recinfo_config() function in open-iscsi (iscsi-initiator-utils). An attacker can craft a malicious SendTargets TargetName containing newline characters and oversized injected keys or values to inject extra configuration lines into persisted node records. When the record is reparsed, due to missing bounds checking, a stack buffer overflow occurs, leading to denial of service or potential memory corruption. The affected component is usr/idbm.c:idbm_recinfo_config in iscsi-initiator-utils, with attacker-controlled input reaching it through SendTargets handling in usr/discovery.c.(CVE-2026-18724)
A vulnerability was found in open-iscsi. In the ICMPv6 echo-reply path of iscsiuio, the code reuses the inbound ipv6_plen field when sizing the reply instead of clamping it to the bytes actually received. An attacker can send a crafted ICMPv6 Echo Request to trigger out-of-bounds reads and a potential one-byte out-of-bounds write, which may impact confidentiality, integrity, and availability.(CVE-2026-18725)
A flaw was found in open-iscsi. This vulnerability allows a remote attacker on the same local network segment to cause a Denial of Service (DoS) in the iscsiuio daemon. By sending a specially crafted Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement with a zero-length option, the attacker can trigger an infinite loop. This leads to sustained CPU usage, rendering the daemon unresponsive and impacting system availability. A secondary risk of out-of-bounds reads exists with a short IPv6 payload, though no memory corruption or data exposure has been confirmed.(CVE-2026-18726)
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.(CVE-2026-18727)
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.(CVE-2026-18728)
- Record
OESA-2026-3511- CVSS 3.1
- 7.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-18728
6.5
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
- Record
UBUNTU-CVE-2026-18728- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-95919 No score
CVE-2026-18728 affecting package iscsi-initiator-utils 2.1.12-1
A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects systems where iscsiuio is actively handling IPv4 DHCP traffic.
- Record
AZL-95919- Updated
- 2026-11-05
OSVopenSUSE-SU-2026:12102-1 No score
iscsiuio-0.7.8.8-114.1 on GA media
These are all security issues fixed in the iscsiuio-0.7.8.8-114.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12102-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
iscsi-initiator-utilsAzure Linux:3 |
through 2.1.12-1 | None known |
open-iscsiDebian:12 |
before 2.1.8-1+deb12u1, plus listed versions 2.1.8-1 |
2.1.8-1+deb12u1 |
open-iscsiDebian:13 |
All versions, plus listed versions 2.1.11-12.1.11-1+deb13u12.1.11-1+deb13u22.1.11-22.1.11-3 Show 6 moreShow less2.1.11-42.1.11-52.1.11-62.1.12-12.1.12-22.1.13-1 |
None known |
open-iscsiDebian:14 |
before 2.1.13-1, plus listed versions 2.1.11-12.1.11-22.1.11-32.1.11-42.1.11-52.1.11-62.1.12-12.1.12-2 |
2.1.13-1 |
open-iscsiopenEuler:20.03-LTS-SP4 From an advisory covering 5 CVEs |
before 2.1.1-18.oe2003sp4 | 2.1.1-18.oe2003sp4 |
open-iscsiUbuntu:14.04:LTS |
All versions, plus listed versions 2.0.873-3ubuntu72.0.873-3ubuntu82.0.873-3ubuntu9 |
None known |
open-iscsiUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 2.0.873-3ubuntu132.0.873+git0.3b4b4500-13ubuntu32.0.873+git0.3b4b4500-14ubuntu12.0.873+git0.3b4b4500-14ubuntu32.0.873+git0.3b4b4500-14ubuntu3.1 Show 7 moreShow less2.0.873+git0.3b4b4500-14ubuntu3.22.0.873+git0.3b4b4500-14ubuntu3.32.0.873+git0.3b4b4500-14ubuntu3.42.0.873+git0.3b4b4500-14ubuntu3.52.0.873+git0.3b4b4500-14ubuntu3.62.0.873+git0.3b4b4500-14ubuntu3.72.0.873+git0.3b4b4500-14ubuntu3.7+esm1 |
None known |
open-iscsiUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2.0.874-4ubuntu32.0.874-4ubuntu42.0.874-4ubuntu52.0.874-5ubuntu12.0.874-5ubuntu2 Show 10 moreShow less2.0.874-5ubuntu2.12.0.874-5ubuntu2.22.0.874-5ubuntu2.32.0.874-5ubuntu2.42.0.874-5ubuntu2.62.0.874-5ubuntu2.72.0.874-5ubuntu2.92.0.874-5ubuntu2.102.0.874-5ubuntu2.112.0.874-5ubuntu2.11+esm1 |
None known |
open-iscsiUbuntu:20.04:LTS |
All versions, plus listed versions 2.0.874-7.1ubuntu32.0.874-7.1ubuntu52.0.874-7.1ubuntu62.0.874-7.1ubuntu6.12.0.874-7.1ubuntu6.22.0.874-7.1ubuntu6.32.0.874-7.1ubuntu6.42.0.874-7.1ubuntu6.5 |
None known |
open-iscsiUbuntu:22.04:LTS |
All versions, plus listed versions 2.1.4-0ubuntu12.1.4-0ubuntu22.1.4-0ubuntu32.1.4-0ubuntu42.1.5-1ubuntu12.1.5-1ubuntu1.12.1.5-1ubuntu1.3 |
None known |
Show 4 moreShow less
| Package | Affected | Fixed |
|---|---|---|
open-iscsiUbuntu:24.04:LTS |
All versions, plus listed versions 2.1.8-1ubuntu22.1.9-3ubuntu12.1.9-3ubuntu22.1.9-3ubuntu32.1.9-3ubuntu4 Show 5 moreShow less2.1.9-3ubuntu5.12.1.9-3ubuntu5.22.1.9-3ubuntu5.32.1.9-3ubuntu5.42.1.9-3ubuntu5.5 |
None known |
open-iscsiUbuntu:26.10 |
All versions, plus listed versions 2.1.11-3ubuntu32.1.11-5ubuntu12.1.11-5ubuntu42.1.11-5ubuntu52.1.11-5ubuntu6 |
None known |
open-iscsiUbuntu:26.04:LTS |
All versions, plus listed versions 2.1.11-1ubuntu32.1.11-3ubuntu12.1.11-3ubuntu22.1.11-3ubuntu32.1.11-3ubuntu3.1 |
None known |
open-iscsiopenSUSE:Tumbleweed From an advisory covering 5 CVEs |
before 2.1.13-114.1 | 2.1.13-114.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| references | CVE List, EUVD, NVD | |
| facts | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-18728 is a medium vulnerability (CVSS 6.5) in Red Hat Enterprise Linux 10, published August 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 24th percentile. Fixed in open-iscsi 2.1.8-1+deb12u1.
References
access.redhat.com/security/cve/CVE-2026-18728
bugzilla.redhat.com/show_bug.cgi?id=2463029
nvd.nist.gov/vuln/detail/CVE-2026-18728
github.com/advisories/GHSA-v5q9-q65g-v5rv
security-tracker.debian.org/tracker/CVE-2026-18728
openeuler.org/zh/security/security-bulletins/detail?id=openEuler-SA-2026-3511
Show 11 moreShow less
nvd.nist.gov/vuln/detail/CVE-2026-18724
nvd.nist.gov/vuln/detail/CVE-2026-18725
nvd.nist.gov/vuln/detail/CVE-2026-18726
nvd.nist.gov/vuln/detail/CVE-2026-18727
ubuntu.com/security/CVE-2026-18728
cve.org/CVERecord?id=CVE-2026-18728
suse.com/security/cve/CVE-2026-18724
suse.com/security/cve/CVE-2026-18725
suse.com/security/cve/CVE-2026-18726
suse.com/security/cve/CVE-2026-18727
suse.com/security/cve/CVE-2026-18728