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CVE Record

CVE-2026-52989: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers Currently, when nvmet_tcp_build_pdu_iovec() detects an out-of-bounds PDU length or offset, it triggers nvmet_tcp_fatal_error(cmd->queue) and returns early. However, because the function returns void, the callers are entirely unaware that a fatal error has occurred and that the cmd->recv_msg.msg_iter was left uninitialized. Callers such as nvmet_tcp_handle_h2c_data_pdu() proceed to blindly overwrite the queue state with queue->rcv_state = NVMET_TCP_RECV_DATA Consequently, the socket receiving loop may attempt to read incoming network data into the uninitialized iterator. Fix this by shifting the error handling responsibility to the callers.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

A flaw in Linux’s NVMe-over-TCP target can mishandle an invalid network message and continue processing with uninitialized state. A remote, unauthenticated peer may trigger unsafe memory access. The supplied CVSS score is 9.8, indicating potentially severe confidentiality, integrity, and availability impact, although the bundle does not document a demonstrated outcome.

Executive priority

Prioritize rapid assessment of storage servers using Linux NVMe-over-TCP targets, especially where initiators cross trust boundaries. Patch confirmed exposures promptly and restrict access while updates are validated. Broad emergency action across every Linux host is not supported because exploitation requires the affected nvmet-tcp target path, and active exploitation is not documented.

Technical view

nvmet_tcp_build_pdu_iovec() detects an out-of-bounds PDU length or offset but previously returned without informing callers. A caller could then set NVMET_TCP_RECV_DATA and let the socket loop receive data through an uninitialized msg_iter. The upstream correction returns errors to callers so they preserve fatal-error handling instead of continuing with invalid receive state.

Likely exposure

Exposure is most likely on Linux systems operating the nvmet-tcp target and accepting NVMe/TCP traffic from untrusted or compromised initiators. Systems not using this component are unlikely to expose the vulnerable path. The supplied version data is unusual and should be reconciled against distribution advisories and exact kernel builds.

Exploitation context

The CVSS vector describes network-accessible, low-complexity, unauthenticated exploitation without user interaction. However, the source bundle marks this CVE as absent from KEV and provides no evidence of active exploitation, public exploit code, or confirmed attacks. Practical exploitability and reliable impact are therefore not established by the supplied evidence.

Researcher notes

The core defect is ignored fatal-error state, categorized as CWE-390. The security consequence arises when receive processing continues with an uninitialized iterator after malformed PDU bounds are detected. The supplied affected-version entries should not be interpreted as simple ranges; validate fixes using distribution backports or the referenced stable commits. No source establishes exploitation reliability or a specific memory-corruption primitive.

Mitigation direction

  • Install a vendor-supported kernel update containing the cited nvmet-tcp error-propagation fix.
  • Confirm the selected distribution package backports the fix, rather than relying only on its version number.
  • Disable nvmet-tcp where it is not operationally required.
  • Restrict NVMe/TCP target access to trusted initiators and storage networks.
  • Consult Linux distribution guidance if an updated package is not yet available.

Validation and detection

  • Inventory hosts loading or configuring the nvmet-tcp target component.
  • Identify exact kernel packages, build revisions, and vendor backport status.
  • Verify the installed source or vendor changelog includes the cited fix.
  • Confirm untrusted networks cannot reach exposed NVMe/TCP target services.
  • Monitor kernel and storage-service logs for fatal receive errors or abnormal crashes.
Prepared
Confidence
medium
Sources
11

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-390: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-52989 mapping review

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
1ADP providers
10Source links

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Linux
7.1CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H1.85.2redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2026-52989Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

redhat-SADPkernel: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers
other:Red Hat severity ratingcvssV3_1
  • 2026-06-24T00:00:00.000Z: Reported to Red Hat.
  • 2026-06-24T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux1385be357e8acd09b36e026567f3a9d5c61139de, dca1a6ba0da9f472ef040525fab10fd9956db59f, 19672ae68d52ff75347ebe2420dde1b07adca09f, ab200d71553bdcf4de554a5985b05b2dd606bc57, 52a0a98549344ca20ad81a4176d68d28e3c05a5c, 52a0a98549344ca20ad81a4176d68d28e3c05a5c, 043b4307a99f902697349128fde93b2ddde4686c, 42afe8ed8ad2de9c19457156244ef3e1eca94b5d, 6.1.163, 6.6.124, 6.12.70, 6.18.10, 5.10.250, 5.15.200unaffected
LinuxLinux6.19, 0, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1affected
Weakness

CWE details

CWE-390

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-390 · source CWE mapping

Detection of Error Condition Without Action

Detection of Error Condition Without Action represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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