Open-iscsi: open-iscsi: denial of service in iscsiuio router advertisement parsing
Published Aug 12, 2026
6.5
MEDIUMCVSS 3.1
EPSS 0.21%
Description
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.
Affected products
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||
|---|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | affected |
| |||
| Red Hat | Red Hat Enterprise Linux 9 | affected |
|
- 9.0
- 10.0
No data.
Red Hat Enterprise Linux 10
iscsi-initiator-utils
Fix deferred
Red Hat Enterprise Linux 9
iscsi-initiator-utils
Fix deferred
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | iscsi-initiator-utils | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | iscsi-initiator-utils | Fix deferred | n/a |
No package ranges for this CVE.
Remediation
Vendor solution
To mitigate this issue, restrict ICMPv6 Router Advertisements from untrusted sources on any network segment where `iscsiuio` interfaces are exposed. Alternatively, disable IPv6 Router Advertisement processing on affected interfaces if not operationally required. This may involve configuring firewall rules to filter ICMPv6 type 134 messages or adjusting network interface settings to prevent RA-driven IPv6 configuration. A service restart may be required for changes to take effect.
Red Hat statement
Moderate: This flaw in `iscsiuio` can lead to a denial of service when processing a specially crafted ICMPv6 Router Advertisement. Exploitation requires an attacker to be on the same Layer 2 network segment as an IPv6-enabled interface handled by `iscsiuio`, limiting its reachability.
Red Hat mitigation
To mitigate this issue, restrict ICMPv6 Router Advertisements from untrusted sources on any network segment where `iscsiuio` interfaces are exposed. Alternatively, disable IPv6 Router Advertisement processing on affected interfaces if not operationally required. This may involve configuring firewall rules to filter ICMPv6 type 134 messages or adjusting network interface settings to prevent RA-driven IPv6 configuration. A service restart may be required for changes to take effect.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Aug 13, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Aug–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.21% (0.00206) | 9.55th | v5 (v2026.06.15) |
| Aug 13, 2026 | 0.21% (0.00215) | 12.06th | v5 (v2026.06.15) |
References (4)
- https://access.redhat.com/security/cve/CVE-2026-18726 vdb-entryx_refsource_REDHATVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2462331 issue-trackingx_refsource_REDHATIssue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2026-18726
- https://www.cve.org/CVERecord?id=CVE-2026-18726
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2026-18726 | vdb-entryx_refsource_REDHATVendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2462331 | issue-trackingx_refsource_REDHATIssue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2026-18726 | ||
| https://www.cve.org/CVERecord?id=CVE-2026-18726 |
Change history (0)
No recorded changes yet.