CVE-2026-74556Network attack vector

Kernel memory corruption via oversized iSCSI response

Published Aug 15, 2026 · Updated Aug 15, 2026

Buffer overflow in the Linux libiscsi_tcp component allows remote attackers controlling an iSCSI target to corrupt kernel memory. The SCSI response path in iscsi_tcp_hdr_dissect() passes an unchecked DataSegmentLength to iscsi_tcp_data_recv_prep(), which copies up to the negotiated limit into an 8,192-byte conn->data buffer. An established iSCSI TCP session with a malicious or compromised target is required; the resulting heap corruption panics the kernel or enables kernel compromise.

CVSS severity9.8
Critical
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in the Linux libiscsi_tcp component allows remote attackers controlling an iSCSI target to corrupt kernel memory. The SCSI response path in iscsi_tcp_hdr_dissect() passes an unchecked DataSegmentLength to iscsi_tcp_data_recv_prep(), which copies up to the negotiated limit into an 8,192-byte conn->data buffer. An established iSCSI TCP session with a malicious or compromised target is required; the resulting heap corruption panics the kernel or enables kernel compromise.

The record

CVE
CVE-2026-74556
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-120, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=2.6.29
  2. Affected versionversion=a081c13e39b5c17052a7b46fafa61019c4c110ff <084af0253673425ce2ae62e3c7f74f0dd023711b
  3. Affected versionversion=a081c13e39b5c17052a7b46fafa61019c4c110ff <72815741715bd41556dac5eeb068bf0f8af06ee7
  4. Affected versionversion=a081c13e39b5c17052a7b46fafa61019c4c110ff <b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676
  5. Affected versionversion=a081c13e39b5c17052a7b46fafa61019c4c110ff <c1dea15f819cded9b3faf58f8bec72323568b6e6
  6. Affected versionversion=a081c13e39b5c17052a7b46fafa61019c4c110ff <c97b5265cc47775f77fd2a23d6bde0426997b233

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.29; version=a081c13e39b5c17052a7b46fafa61019c4c110ff <084af0253673425ce2ae62e3c7f74f0dd023711b; version=a081c13e39b5c17052a7b46fafa61019c4c110ff <72815741715bd41556dac5eeb068bf0f8af06ee7; version=a081c13e39b5c17052a7b46fafa61019c4c110ff <b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676; version=a081c13e39b5c17052a7b46fafa61019c4c110ff <c1dea15f819cded9b3faf58f8bec72323568b6e6; version=a081c13e39b5c17052a7b46fafa61019c4c110ff <c97b5265cc47775f77fd2a23d6bde0426997b233

Published CVSS scores

7.2Red HatCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
9.8Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1203Exploitation for Client Execution

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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