CVE-2026-64534

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-27. A secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path

In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected, nvmet_req_uninit() is called unconditionally. However, if the command arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init() had returned false and percpu_ref_tryget_live() was never executed. The unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a refcount underflow, leading to a WARNING in percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and eventually a permanent workqueue deadlock.

Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling nvmet_req_uninit(), matching the existing pattern in nvmet_tcp_execute_request().

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
34th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-19). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 27, 2026

Last Modified

October 19, 2026

Advisory Details (7)

Auto-updated Oct 19, 2026
Patch available.
Web page

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1
Web page

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc
Web page

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b
Web page

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e
Web page

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8
Web page

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f
Web page

nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf

Patch Availability(19)

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

(6 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (55 versions)
  • every version up to 5.10.262-1: fixed in 5.10.262-1
—
linux-6.16.1.106-3~deb11u1 ... 6.1.177-1~deb11u1 (22 versions)
  • every version up to 6.1.180-1~deb11u1: fixed in 6.1.180-1~deb11u1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (55 versions)
  • every version up to 6.1.180-1: fixed in 6.1.180-1
—
linux-6.12—
  • every version up to 6.12.100-1~deb12u1: fixed in 6.12.100-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.96-1 (31 versions)
  • every version up to 6.12.100-1: fixed in 6.12.100-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (157 versions)
  • every version up to 7.1.3-1: fixed in 7.1.3-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(15)

Data Freshness Timeline

(refreshed 37× in last 7d / 116× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 575 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 475 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 21:31 UTCEG score recompute
  2. 2026-10-19 21:31 UTCVendor advisory
  3. 2026-10-19 21:30 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-19 20:54 UTCEG score recompute
  5. 2026-10-19 20:54 UTCVendor advisory
  6. 2026-10-19 20:53 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  8. 2026-10-19 13:25 UTCEG score recompute
  9. 2026-10-19 13:25 UTCVendor advisory
  10. 2026-10-19 13:25 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  12. 2026-10-18 13:20 UTCVendor advisory
  13. 2026-10-18 13:20 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  14. 2026-10-18 03:22 UTCEG score recompute
  15. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  16. 2026-10-17 15:01 UTCEG score recompute
  17. 2026-10-17 15:01 UTCVendor advisory
  18. 2026-10-17 15:00 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  20. 2026-10-16 16:41 UTCEG score recompute
  21. 2026-10-16 16:41 UTCVendor advisory
  22. 2026-10-16 16:40 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-16 15:49 UTCEG score recompute
  24. 2026-10-16 15:49 UTCVendor advisory
  25. 2026-10-16 15:49 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
Show 75 more
  1. 2026-10-16 12:20 UTCEG score recompute
  2. 2026-10-16 12:20 UTCVendor advisory
  3. 2026-10-16 12:20 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  5. 2026-10-15 13:56 UTCEG score recompute
  6. 2026-10-15 13:56 UTCVendor advisory
  7. 2026-10-15 13:55 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  9. 2026-10-14 08:48 UTCEG score recompute
  10. 2026-10-14 08:48 UTCVendor advisory
  11. 2026-10-14 08:47 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  13. 2026-10-13 04:28 UTCEG score recompute
  14. 2026-10-13 04:28 UTCVendor advisory
  15. 2026-10-13 04:28 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  17. 2026-10-12 15:47 UTCEG score recompute
  18. 2026-10-12 06:09 UTCVendor advisory
  19. 2026-10-12 06:08 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-11 19:32 UTCEG score recompute
  21. 2026-10-11 16:47 UTCEG score recompute
  22. 2026-10-11 14:09 UTCEG score recompute
  23. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  24. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  25. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  26. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  27. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  28. 2026-10-07 04:16 UTCEG score recompute
  29. 2026-10-07 04:16 UTCVendor advisory
  30. 2026-10-07 04:16 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  32. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  33. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  34. 2026-10-04 12:38 UTCVendor advisory
  35. 2026-10-04 12:38 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  36. 2026-10-04 07:21 UTCEG score recompute
  37. 2026-10-04 07:21 UTCVendor advisory
  38. 2026-10-04 07:21 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  39. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  40. 2026-10-03 03:14 UTCVendor advisory
  41. 2026-10-03 03:14 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  42. 2026-10-02 18:30 UTCEG score recompute
  43. 2026-10-02 18:30 UTCVendor advisory
  44. 2026-10-02 18:29 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  46. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  47. 2026-10-01 16:12 UTCVendor advisory
  48. 2026-10-01 16:12 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-10-01 12:13 UTCVendor advisory
  50. 2026-10-01 12:13 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  51. 2026-10-01 07:54 UTCVendor advisory
  52. 2026-10-01 07:54 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-01 03:55 UTCEG score recompute
  54. 2026-10-01 03:55 UTCVendor advisory
  55. 2026-10-01 03:55 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  56. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  57. 2026-09-29 07:56 UTCEG score recompute
  58. 2026-09-29 07:56 UTCVendor advisory
  59. 2026-09-29 07:56 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  60. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  61. 2026-09-28 12:58 UTCVendor advisory
  62. 2026-09-28 12:58 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-09-28 08:12 UTCVendor advisory
  64. 2026-09-28 08:12 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-09-28 04:01 UTCEG score recompute
  66. 2026-09-28 04:01 UTCVendor advisory
  67. 2026-09-28 04:01 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  69. 2026-09-25 07:26 UTCEG score recompute
  70. 2026-09-25 07:26 UTCVendor advisory
  71. 2026-09-25 07:26 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-09-24 10:23 UTCVendor advisory
  73. 2026-09-24 10:23 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  74. 2026-09-24 06:22 UTCVendor advisory
  75. 2026-09-24 06:22 UTCGHSA enrichmentGHSA-6vg3-7hp6-mqc5 · GitHub severity CRITICAL · GitHub CVSS 9.8

Frequently asked(5)

What is CVE-2026-64534?
CVE-2026-64534 is a critical-severity vulnerability; its CVE record was published on July 27, 2026. In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: check INITFAILED before nvmetreq_uninit in digest error path In nvmettcptryrecvddgst(), when a data digest mismatch is detected, nvmetrequninit() is called unconditionally. However, if the command arrived via the…
When was the CVE record for CVE-2026-64534 published?
The CVE record for CVE-2026-64534 was published on July 27, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 19, 2026; the record at its source may have been updated since.
Is CVE-2026-64534 actively exploited?
CVE-2026-64534 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64534?
CVE-2026-64534 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-64534?
A fix for CVE-2026-64534 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64534 are linked in the Vendor Advisories panel on this page.

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