CVE-2026-74556

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-15. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — Patch released this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

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.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
34%
KEV
Not listed

Published

August 15, 2026

Last Modified

August 19, 2026

Advisory Details (8)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f1a3a51fc5dba0e99532379665069f1700da6b44
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c97b5265cc47775f77fd2a23d6bde0426997b233
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c1dea15f819cded9b3faf58f8bec72323568b6e6
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b0aa3e8e2ab4ca92adb28a3ef41873b3363b8676
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a8f94cc9f0e5759252551be3a172960c57f21f54
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a51812842084fd390590ab8dc0431f10c73ddc56
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/72815741715bd41556dac5eeb068bf0f8af06ee7
generic

scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/084af0253673425ce2ae62e3c7f74f0dd023711b

Vendor Advisories for CVE-2026-74556(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1035.38) @ noble2026-09-19ubuntu
redhatkernel-0:4.18.0-553.163.1.el8_102026-09-15redhat
redhatkernel-rt-0:4.18.0-553.163.1.rt7.504.el8_102026-09-15redhat
redhatkernel-0:5.14.0-687.48.1.el9_82026-09-15redhat
redhatkernel-0:6.12.0-211.55.1.el10_22026-09-15redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (56 versions)6.1.187-1
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.12.96-1 (33 versions)6.12.105-1
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (164 versions)7.1.8-1

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 83× in last 7d / 241× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 281 total refreshes for this CVE.

  1. 2026-09-19 06:54 UTCVendor advisory
  2. 2026-09-19 06:54 UTCGHSA enrichment
  3. 2026-09-19 02:21 UTCVendor advisory
  4. 2026-09-19 02:21 UTCGHSA enrichment
  5. 2026-09-18 21:57 UTCEG score recompute
  6. 2026-09-18 21:57 UTCVendor advisory
  7. 2026-09-18 21:57 UTCGHSA enrichment
  8. 2026-09-18 19:28 UTCEPSS rescore
  9. 2026-09-18 16:48 UTCVendor advisory
  10. 2026-09-18 16:48 UTCGHSA enrichment
  11. 2026-09-18 11:11 UTCVendor advisory
  12. 2026-09-18 11:11 UTCGHSA enrichment
  13. 2026-09-18 06:49 UTCVendor advisory
  14. 2026-09-18 06:49 UTCGHSA enrichment
  15. 2026-09-18 02:27 UTCVendor advisory
  16. 2026-09-18 02:27 UTCGHSA enrichment
  17. 2026-09-17 22:05 UTCEG score recompute
  18. 2026-09-17 22:05 UTCVendor advisory
  19. 2026-09-17 22:05 UTCGHSA enrichment
  20. 2026-09-17 13:14 UTCVendor advisory
  21. 2026-09-17 13:14 UTCGHSA enrichment
  22. 2026-09-17 08:08 UTCVendor advisory
  23. 2026-09-17 08:08 UTCGHSA enrichment
  24. 2026-09-17 03:46 UTCVendor advisory
  25. 2026-09-17 03:46 UTCGHSA enrichment
Show 75 more
  1. 2026-09-16 23:24 UTCVendor advisory
  2. 2026-09-16 23:24 UTCGHSA enrichment
  3. 2026-09-16 16:08 UTCEG score recompute
  4. 2026-09-16 16:08 UTCVendor advisory
  5. 2026-09-16 16:08 UTCGHSA enrichment
  6. 2026-09-16 14:08 UTCEPSS rescore
  7. 2026-09-16 10:47 UTCVendor advisory
  8. 2026-09-16 10:47 UTCGHSA enrichment
  9. 2026-09-16 06:16 UTCEG score recompute
  10. 2026-09-16 06:16 UTCVendor advisory
  11. 2026-09-16 06:16 UTCGHSA enrichment
  12. 2026-09-16 05:15 UTCEPSS rescore
  13. 2026-09-16 01:54 UTCVendor advisory
  14. 2026-09-16 01:54 UTCGHSA enrichment
  15. 2026-09-15 21:32 UTCVendor advisory
  16. 2026-09-15 21:31 UTCGHSA enrichment
  17. 2026-09-15 16:11 UTCVendor advisory
  18. 2026-09-15 16:11 UTCGHSA enrichment
  19. 2026-09-15 11:49 UTCVendor advisory
  20. 2026-09-15 11:49 UTCGHSA enrichment
  21. 2026-09-15 05:56 UTCEG score recompute
  22. 2026-09-15 05:56 UTCVendor advisory
  23. 2026-09-15 05:56 UTCGHSA enrichment
  24. 2026-09-15 03:12 UTCEPSS rescore
  25. 2026-09-15 00:27 UTCVendor advisory
  26. 2026-09-15 00:27 UTCGHSA enrichment
  27. 2026-09-14 20:05 UTCEG score recompute
  28. 2026-09-14 20:05 UTCVendor advisory
  29. 2026-09-14 20:05 UTCGHSA enrichment
  30. 2026-09-14 13:01 UTCVendor advisory
  31. 2026-09-14 13:01 UTCGHSA enrichment
  32. 2026-09-14 08:39 UTCVendor advisory
  33. 2026-09-14 08:39 UTCGHSA enrichment
  34. 2026-09-14 04:17 UTCVendor advisory
  35. 2026-09-14 04:17 UTCGHSA enrichment
  36. 2026-09-13 23:55 UTCVendor advisory
  37. 2026-09-13 23:55 UTCGHSA enrichment
  38. 2026-09-13 19:33 UTCEG score recompute
  39. 2026-09-13 19:33 UTCVendor advisory
  40. 2026-09-13 19:33 UTCGHSA enrichment
  41. 2026-09-13 15:11 UTCVendor advisory
  42. 2026-09-13 15:11 UTCGHSA enrichment
  43. 2026-09-13 10:47 UTCVendor advisory
  44. 2026-09-13 10:47 UTCGHSA enrichment
  45. 2026-09-13 06:24 UTCVendor advisory
  46. 2026-09-13 06:24 UTCGHSA enrichment
  47. 2026-09-13 02:02 UTCVendor advisory
  48. 2026-09-13 02:02 UTCGHSA enrichment
  49. 2026-09-12 21:40 UTCVendor advisory
  50. 2026-09-12 21:40 UTCGHSA enrichment
  51. 2026-09-12 17:18 UTCEG score recompute
  52. 2026-09-12 17:18 UTCVendor advisory
  53. 2026-09-12 17:18 UTCGHSA enrichment
  54. 2026-09-12 15:02 UTCEPSS rescore
  55. 2026-09-12 12:56 UTCVendor advisory
  56. 2026-09-12 12:56 UTCGHSA enrichment
  57. 2026-09-12 08:34 UTCVendor advisory
  58. 2026-09-12 08:34 UTCGHSA enrichment
  59. 2026-09-12 04:12 UTCVendor advisory
  60. 2026-09-12 04:12 UTCGHSA enrichment
  61. 2026-09-11 23:50 UTCVendor advisory
  62. 2026-09-11 23:50 UTCGHSA enrichment
  63. 2026-09-11 18:16 UTCEG score recompute
  64. 2026-09-11 18:16 UTCVendor advisory
  65. 2026-09-11 18:16 UTCGHSA enrichment
  66. 2026-09-11 14:53 UTCEPSS rescore
  67. 2026-09-11 13:53 UTCEG score recompute
  68. 2026-09-11 13:53 UTCGHSA enrichment
  69. 2026-09-11 09:31 UTCGHSA enrichment
  70. 2026-09-11 05:09 UTCGHSA enrichment
  71. 2026-09-11 00:47 UTCGHSA enrichment
  72. 2026-09-10 18:52 UTCGHSA enrichment
  73. 2026-09-10 14:27 UTCGHSA enrichment
  74. 2026-09-10 10:03 UTCEG score recompute
  75. 2026-09-10 10:03 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-74556?
CVE-2026-74556 is a critical vulnerability published on August 15, 2026. In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer iscsitcphdr_dissect() receives the data segment of several PDU types into the fixed-size conn->data buffer, which is allocated for ISCSIDEFMAXRECVSEGLEN…
When was CVE-2026-74556 disclosed?
CVE-2026-74556 was first published in the National Vulnerability Database on August 15, 2026, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74556 actively exploited?
CVE-2026-74556 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 66.1% of all scored CVEs.
What is the CVSS score of CVE-2026-74556?
CVE-2026-74556 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74556?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74556, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-74556

Explore →

Is Your Infrastructure Affected by CVE-2026-74556?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.