nvme-tcp: fix host memory disclosure on R2T for a read command (CVE-2026-89481) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89481

nvme-tcp: fix host memory disclosure on R2T for a read command

Answer in brief

CVE-2026-89481 records a Unknown severity vulnerability in nvme-tcp: fix host memory disclosure on R2T for a read command. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=3f2304f8c6d6ed97849057bd16fee99e434ca796 <a4c3c7310156493797c920b10d8648c07aa05403 \|\| >=3f2304f8c6d6ed97849057bd16fee99e434ca796 <3b3d27670c0c890ba7cf1bc3614cab61bde6d25c \|\| >=3f2304f8c6d6ed97849057bd16fee99e434ca796 <3a0b05145053a5fad1a2ddb4e4d87b07385e63e5 \|\| >=3f2304f8c6d6ed97849057bd16fee99e434ca796 <6efbc52237facda35d2d874fe1765bb4839275d8	a4c3c7310156493797c920b10d8648c07aa05403, 3b3d27670c0c890ba7cf1bc3614cab61bde6d25c, 3a0b05145053a5fad1a2ddb4e4d87b07385e63e5, 6efbc52237facda35d2d874fe1765bb4839275d8
Linux/Linuxgeneric	5.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to a4c3c7310156493797c920b10d8648c07aa05403 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix host memory disclosure on R2T for a read command nvme_tcp_handle_r2t() does not check the direction of the request the R2T refers to. A malicious controller can send an R2T for a READ and the host will answer it: nvme_tcp_setup_h2c_data_pdu() builds the H2CData header and nvme_tcp_try_send_data() sends the request's data buffer. That buffer is the READ destination, so its contents go to the controller. The command then completes normally and nothing is logged. Against a test controller that answers every READ with an R2T, a 4096 byte buffered read returned all 4096 bytes, split over two R2Ts. The pages contained stale kernel data, including an array of struct page pointers. Reject an R2T for a request that is not a write.

Quoted source text, attributed separately from HOL analysis.