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NVD / CVE Program· CNA Linux

CVE-2026-64534: nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path

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: 0.32% (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 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf, 2ed3c9d955e8cd6361f130623baa664a75fb345f, 4606467a75cfc16721937272ed29462a750b60c8; azl3 kernel 6.6.145.2-1 on Azure Linux 3.0 6.6.150.1-1.

Low priority for now. Upgrade to Linux Linux 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf, 2ed3c9d955e8cd6361f130623baa664a75fb345f, 4606467a75cfc16721937272ed29462a750b60c8; azl3 kernel 6.6.145.2-1 on Azure Linux 3.0 6.6.150.1-1 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: 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().

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Jul 27, 2026
Updated
Nov 3, 2026
EPSS
0.3% · 25th percentile

Report tools

JSON

Action score

39

Monitor

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.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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  • when exploit code appears or is weaponized
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Noroxi 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.

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Affected 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

    • 4b17476d809273617d3317fa0d4ae78aa488d760, 5.12affected
    • 91edfca6f8b364d60cde3ddefaf7d03ddf35774b and later · before 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decfaffected · git
    • fda871c0ba5d2eed2cd1c881573168129da70058 and later · before ba35b1c674ca3841c0dfadd698f2c1b3ec542d4eaffected · git
    • fda871c0ba5d2eed2cd1c881573168129da70058 and later · before c7874dad84b20433c0fe3919f291a762d40de08baffected · git
    • fda871c0ba5d2eed2cd1c881573168129da70058 and later · before e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1affected · git
    • fda871c0ba5d2eed2cd1c881573168129da70058 and later · before d306da8833e75f669d93424fd84940236f3850bcaffected · git
    • fda871c0ba5d2eed2cd1c881573168129da70058 and later · before 2ed3c9d955e8cd6361f130623baa664a75fb345faffected · git
    • fda871c0ba5d2eed2cd1c881573168129da70058 and later · before 4606467a75cfc16721937272ed29462a750b60c8affected · git
    • 5.10.20 and later · before 5.10.261affected · semver
    • 5.11.3 and later · before 5.12affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debug-modules-extrabefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-debug-uki-virtbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-develbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-devel-matchedbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-docbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-headersbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-modulesbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-modules-corebefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-modules-extrabefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-modules-extra-matchedbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-rtbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-rt-64kbefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2
AlmaLinux:10kernel-rt-64k-corebefore 6.12.0-211.58.1.el10_26.12.0-211.58.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-64532Jul 27, 2026 · fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation}
    31Monitor
  • ← EarlierCVE-2026-64533Jul 27, 2026 · fs/ntfs3: validate lcns_follow in log_replay conversion
    31Monitor
  • Later →CVE-2026-64535Jul 27, 2026 · nvmet-tcp: Fix potential UAF when ddgst mismatch
    39Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux22ec7a9fe9153d2737ee9b2fa6d2e43a1491decfVendor (CNA)
Linux Linux2ed3c9d955e8cd6361f130623baa664a75fb345fVendor (CNA)
Linux Linux4606467a75cfc16721937272ed29462a750b60c8Vendor (CNA)
Linux Linux5.10.261Vendor (CNA)
Linux Linux5.12Vendor (CNA)
Linux Linuxba35b1c674ca3841c0dfadd698f2c1b3ec542d4eVendor (CNA)
Linux Linuxc7874dad84b20433c0fe3919f291a762d40de08bVendor (CNA)
Linux Linuxd306da8833e75f669d93424fd84940236f3850bcVendor (CNA)
Linux Linuxe602c93b25bda4a9d0ff1791a4bdbfdcbb074af1Vendor (CNA)
azl3 kernel 6.6.145.2-1 on Azure Linux 3.06.6.150.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.166.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package registry (OSV)
red hat:bpftool0:4.18.0-553.166.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.166.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.166.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.166.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.166.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-553.166.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+8

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-7210019 days apartdm-integrity: fix a bug if the bio is out of limits
    35Monitor
  • CVE-2026-6808514 days apartBluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled
    32Monitor
  • CVE-2026-7201219 days aparttracing/osnoise: Call synchronize_rcu() when unregistering
    31Monitor
  • CVE-2025-68770195 days apartbnxt_en: Fix XDP_TX path
    30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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)

CWE-667 · Improper Locking

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.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records