CVE-2026-55995Network attack vector

Service crash via stale iSNS attribute pointers

Published Jul 29, 2026 · Updated Jul 29, 2026

Double free in the iSNS attribute decoder in Open-iSCSI allows man-in-the-middle attackers to crash affected services. When buf_get fails in attrs.c, two decode functions free string or opaque-attribute storage but leave its pointer non-null, enabling later cleanup to free it again. Exploitation requires interception of iSNS traffic and malformed attribute data; the published impact is availability loss without data disclosure or modification.

CVSS severity8.7
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in the iSNS attribute decoder in Open-iSCSI allows man-in-the-middle attackers to crash affected services. When buf_get fails in attrs.c, two decode functions free string or opaque-attribute storage but leave its pointer non-null, enabling later cleanup to free it again. Exploitation requires interception of iSNS traffic and malformed attribute data; the published impact is availability loss without data disclosure or modification.

The record

CVE
CVE-2026-55995
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
Open-iSCSI
Product
Open-iSCSI
Classifications
CWE-415, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=? <=56718d4e9d1a4f51c30697b5c0534144bb41c9bb

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open-iSCSI · Open-iSCSIversion=? <=56718d4e9d1a4f51c30697b5c0534144bb41c9bb

Published CVSS scores

8.7SUSECVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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