Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Network vector but the required MITM position makes it AC:H; no auth (PR:N) or interaction, and impact is availability-only (A:H, C/I:N).
AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from Vendor (suse).
CVSS VectorVendor: suse
Lifecycle Timeline
3DescriptionCVE.org
A Double Free vulnerability in open-iscsi allows an unauthenticated MITM attacker to cause DoS.
This issue affects open-iscsi: from ? through 56718d4e9d1a4f51c30697b5c0534144bb41c9bb.
AnalysisAI
Denial of service in open-iscsi's bundled open-isns library (iSNS implementation) lets an unauthenticated man-in-the-middle attacker crash the iSNS client/server by triggering a double free in the attribute-decoding routines. The flaw stems from freed pointers not being nulled in isns_attr_type_string_decode and isns_attr_type_opaque_decode, so a crafted iSNS message causes the same allocation to be freed twice. There is no public exploit identified at time of analysis and it is not listed in CISA KEV; impact is limited to availability, with no confidentiality or integrity effect.
Technical ContextAI
The affected code is open-isns, the reference implementation of the Internet Storage Name Service (iSNS) protocol used by open-iscsi to discover and manage iSCSI/iFCP storage targets. The vulnerability is a classic CWE-415 Double Free: in attrs.c, isns_attr_type_string_decode and isns_attr_type_opaque_decode free a buffer on a decode error but leave value->iv_string / value->iv_opaque.ptr dangling, so a later cleanup pass frees the same memory again. The fix commit (56718d4e9d1a4f51c30697b5c0534144bb41c9bb) simply sets these pointers to NULL after freeing. Because attribute decoding runs on network-supplied iSNS PDUs, an attacker who can inject or alter iSNS traffic controls the malformed input that reaches this path.
RemediationAI
Upstream fix available (commit 56718d4e9d1a4f51c30697b5c0534144bb41c9bb); a released patched version is not independently confirmed from the input, so update open-isns/open-iscsi to a distribution build that incorporates this commit as soon as your vendor ships it - track the SUSE bug at https://bugzilla.suse.com/show_bug.cgi?id=CVE-2026-55995 and the upstream commit at https://github.com/open-iscsi/open-isns/commit/56718d4e9d1a4f51c30697b5c0534144bb41c9bb. As compensating controls until patched: if iSNS discovery is not used, disable it in your iSCSI initiator/target configuration to remove the vulnerable code path entirely; where iSNS is required, restrict iSNS server/client communication to a dedicated, isolated storage VLAN and enforce authenticated/integrity-protected transport (e.g., IPsec) to deny the MITM position the attack depends on. The trade-off of disabling iSNS is loss of automatic target discovery (requiring static target configuration), and network isolation/IPsec adds operational overhead but directly negates the required attacker position.
More in Open Iscsi
View allAn issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products. Rated high severity (CVSS 8.2), this vuln
An issue was discovered in Open-iSCSI through 2.0.875. Rated high severity (CVSS 7.8), this vulnerability is low attack
An issue was discovered in Contiki through 3.0. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitab
Same weakness CWE-415 – Double Free
View allSame technique Information Disclosure
View allVendor StatusVendor
SUSE
Severity: Important| Product | Status |
|---|---|
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server 15 SP7 | Affected |
| SUSE Linux Enterprise Server 16.0 | Affected |
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Micro 6.0 | Affected |
| SUSE Linux Micro 6.1 | Affected |
| SUSE Linux Micro 6.2 | Affected |
| openSUSE Leap 16.0 | Affected |
| SUSE Linux Enterprise High Performance Computing 12 SP5 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP6 | Affected |
| SUSE Linux Enterprise Server 12 SP5 | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Affected |
| SUSE Linux Enterprise Server 15 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5 | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP6 | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Affected |
| SUSE Manager Proxy 4.3 | Affected |
| SUSE Manager Proxy LTS 4.3 | Affected |
| SUSE Manager Retail Branch Server 4.3 | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | Affected |
| SUSE Manager Server 4.3 | Affected |
| SUSE Manager Server LTS 4.3 | Affected |
| SUSE CaaS Platform 4.0 | Affected |
| SUSE Enterprise Storage 6 | Affected |
| SUSE Enterprise Storage 7 | Affected |
| SUSE Enterprise Storage 7.1 | Affected |
| SUSE Linux Enterprise High Performance Computing 12 SP3 | Affected |
| SUSE Linux Enterprise High Performance Computing 12 SP4 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Affected |
| SUSE Linux Enterprise High Performance Computing 15-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15-LTSS | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP1 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Affected |
| SUSE Linux Enterprise Server 12 SP3 | Affected |
| SUSE Linux Enterprise Server 12 SP3-BCL | Affected |
| SUSE Linux Enterprise Server 12 SP3-ESPOS | Affected |
| SUSE Linux Enterprise Server 12 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP4 | Affected |
| SUSE Linux Enterprise Server 12 SP4-ESPOS | Affected |
| SUSE Linux Enterprise Server 12 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 | Affected |
| SUSE Linux Enterprise Server 15 SP1 | Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP2 | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP3 | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server 15-LTSS | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP3 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Affected |
| SUSE Manager Proxy 4.0 | Affected |
| SUSE Manager Proxy 4.1 | Affected |
| SUSE Manager Proxy 4.2 | Affected |
| SUSE Manager Retail Branch Server 4.0 | Affected |
| SUSE Manager Retail Branch Server 4.1 | Affected |
| SUSE Manager Retail Branch Server 4.2 | Affected |
| SUSE Manager Server 4.0 | Affected |
| SUSE Manager Server 4.1 | Affected |
| SUSE Manager Server 4.2 | Affected |
| SUSE OpenStack Cloud 8 | Affected |
| SUSE OpenStack Cloud 9 | Affected |
| SUSE OpenStack Cloud Crowbar 8 | Affected |
| SUSE OpenStack Cloud Crowbar 9 | Affected |
| openSUSE Leap 15.3 | Affected |
| openSUSE Leap 15.4 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
| SLES-CHOST-BYOS-Aliyun | Affected |
| SLES-CHOST-BYOS-Azure | Affected |
| SLES-CHOST-BYOS-EC2 | Affected |
| SLES-CHOST-BYOS-GCE | Affected |
| SLES-CHOST-BYOS-GDC | Affected |
| SLES-CHOST-BYOS-SAP-CCloud | Affected |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-50330
GHSA-93fw-mwmg-2g5m