CVE-2026-74556: scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer
Noroxi assessment
Priority: Monitor (action score 39/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.39% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: Linux Linux 084af0253673425ce2ae62e3c7f74f0dd023711b, 72815741715bd41556dac5eeb068bf0f8af06ee7, a51812842084fd390590ab8dc0431f10c73ddc56; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 084af0253673425ce2ae62e3c7f74f0dd023711b, 72815741715bd41556dac5eeb068bf0f8af06ee7, a51812842084fd390590ab8dc0431f10c73ddc56; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer iscsi_tcp_hdr_dissect() receives the data segment of several PDU types into the fixed-size conn->data buffer, which is allocated for ISCSI_DEF_MAX_RECV_SEG_LEN (8192) bytes. For the LOGIN_RSP, TEXT_RSP, REJECT and ASYNC_EVENT opcodes the dissect path already rejects a PDU whose DataSegmentLength exceeds that buffer. The SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) path also copies its data segment (sense/response data) into conn->data via iscsi_tcp_data_recv_prep(), but it does so without the same check. The only upstream bound on in.datalen is conn->max_recv_dlength, the initiator's advertised MaxRecvDataSegmentLength, which is commonly negotiated well above 8192 (open-iscsi defaults to 262144). A target that returns a SCSI Response with a DataSegmentLength between 8193 and max_recv_dlength therefore overflows the 8192-byte conn->data buffer. Once the same bound applies, ISCSI_OP_SCSI_CMD_RSP is handled exactly like those responses: bound the data segment, receive it into conn->data when present, and otherwise complete the PDU with no data. Fold the opcode into that case group rather than duplicating the check.
- Published
- Aug 15, 2026
- Updated
- Oct 16, 2026
- EPSS
- 0.3% · 34th percentile
- CWE
- —
Report tools
Action score
39
Low priority for now.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 9.8
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 2.6.29affected
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before a51812842084fd390590ab8dc0431f10c73ddc56affected · git
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before a8f94cc9f0e5759252551be3a172960c57f21f54affected · git
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before f1a3a51fc5dba0e99532379665069f1700da6b44affected · git
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before c97b5265cc47775f77fd2a23d6bde0426997b233affected · git
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before 084af0253673425ce2ae62e3c7f74f0dd023711baffected · git
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before 72815741715bd41556dac5eeb068bf0f8af06ee7affected · git
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676affected · git
- a081c13e39b5c17052a7b46fafa61019c4c110ff and later · before c1dea15f819cded9b3faf58f8bec72323568b6e6affected · git
- before 2.6.29not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | bpftool | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-abi-stablelists | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-core | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-cross-headers | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-debug | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-debug-core | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-debug-devel | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules-extra | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-devel | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-doc | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-headers | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-modules | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-modules-extra | before 4.18.0-553.163.1.el8_10 | 4.18.0-553.163.1.el8_10 |
| AlmaLinux:8 | kernel-rt | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-core | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-debug | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-core | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-devel | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules-extra | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-devel | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
| AlmaLinux:8 | kernel-rt-modules | before 4.18.0-553.163.1.rt7.504.el8_10 | 4.18.0-553.163.1.rt7.504.el8_10 |
+96
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-74550Aug 15, 2026 · net: do not send ICMP/NDISC Redirects when peer allocation fails30Monitor
- ← EarlierCVE-2026-74554Aug 15, 2026 · wifi: ath12k: fix out-of-bounds clear_bit in ath12k_mac_dp_peer_cleanup()35Monitor
- Later →CVE-2026-74557Aug 15, 2026 · scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 084af0253673425ce2ae62e3c7f74f0dd023711b | Vendor (CNA) |
| Linux Linux | 72815741715bd41556dac5eeb068bf0f8af06ee7 | Vendor (CNA) |
| Linux Linux | a51812842084fd390590ab8dc0431f10c73ddc56 | Vendor (CNA) |
| Linux Linux | a8f94cc9f0e5759252551be3a172960c57f21f54 | Vendor (CNA) |
| Linux Linux | b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676 | Vendor (CNA) |
| Linux Linux | c1dea15f819cded9b3faf58f8bec72323568b6e6 | Vendor (CNA) |
| Linux Linux | c97b5265cc47775f77fd2a23d6bde0426997b233 | Vendor (CNA) |
| Linux Linux | f1a3a51fc5dba0e99532379665069f1700da6b44 | Vendor (CNA) |
| azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 | 6.6.152.1-1 · Release Notes | Microsoft (MSRC) |
| almalinux:bpftool | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-abi-stablelists | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-core | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-cross-headers | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-core | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-devel | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-modules | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-modules-extra | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-devel | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-doc | 4.18.0-553.163.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| debian:linux | 6.1.187-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.107-1~deb12u1 · Debian:12 | Package registry (OSV) |
| red hat:bpftool | 0:4.18.0-553.163.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:bpftool-debuginfo | 0:4.18.0-553.163.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel | 0:4.18.0-553.163.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-abi-stablelists | 0:4.18.0-553.163.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-core | 0:4.18.0-553.163.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug | 0:4.18.0-553.163.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug-core | 0:4.18.0-553.163.1.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
+14
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0854 · Aug 19, 2026(Linux Kernel Güvenlik Bildirimi)
Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (2)
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/72815741715bd41556dac5eeb068bf0f8af06ee7
- git.kernel.org/stable/c/a51812842084fd390590ab8dc0431f10c73ddc56
- git.kernel.org/stable/c/a8f94cc9f0e5759252551be3a172960c57f21f54
- git.kernel.org/stable/c/b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676
- git.kernel.org/stable/c/c1dea15f819cded9b3faf58f8bec72323568b6e6
- git.kernel.org/stable/c/c97b5265cc47775f77fd2a23d6bde0426997b233
- git.kernel.org/stable/c/f1a3a51fc5dba0e99532379665069f1700da6b44
Vendor advisories and official records. Exploit/PoC links are deliberately left out.