nvme-tcp: fix host memory disclosure on R2T for a read command
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.
- Published
- Sep 11, 2026
- Updated
- Sep 14, 2026
- EPSS
- 0.4% · 34th percentile
- CWE
- —
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.5
- 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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
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
- 5.0affected
- 3f2304f8c6d6ed97849057bd16fee99e434ca796 and later · before 49a4dcf57608ebf6432dbcb203ed25e7ed581445affected · git
- 3f2304f8c6d6ed97849057bd16fee99e434ca796 and later · before bc4013c7cce58d46f792c8c87bc8c8318a70190eaffected · git
- 3f2304f8c6d6ed97849057bd16fee99e434ca796 and later · before a4c3c7310156493797c920b10d8648c07aa05403affected · git
- 3f2304f8c6d6ed97849057bd16fee99e434ca796 and later · before 3b3d27670c0c890ba7cf1bc3614cab61bde6d25caffected · git
- 3f2304f8c6d6ed97849057bd16fee99e434ca796 and later · before 3a0b05145053a5fad1a2ddb4e4d87b07385e63e5affected · git
- 3f2304f8c6d6ed97849057bd16fee99e434ca796 and later · before 6efbc52237facda35d2d874fe1765bb4839275d8affected · git
- before 5.0not affected · semver
- 6.1.188 and later · up to and including 6.1.*not affected · semver
- 6.6.157 and later · up to and including 6.6.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | all versions | — |
| Debian:12 | linux-6.12 | before 6.12.111-1~deb12u1 | 6.12.111-1~deb12u1 |
| Debian:13 | linux | before 6.12.111-1 | 6.12.111-1 |
| Debian:14 | linux | before 7.2.6-1 | 7.2.6-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 3a0b05145053a5fad1a2ddb4e4d87b07385e63e5 | Vendor (CNA) |
| Linux Linux | 3b3d27670c0c890ba7cf1bc3614cab61bde6d25c | Vendor (CNA) |
| Linux Linux | 49a4dcf57608ebf6432dbcb203ed25e7ed581445 | Vendor (CNA) |
| Linux Linux | 6efbc52237facda35d2d874fe1765bb4839275d8 | Vendor (CNA) |
| Linux Linux | a4c3c7310156493797c920b10d8648c07aa05403 | Vendor (CNA) |
| Linux Linux | bc4013c7cce58d46f792c8c87bc8c8318a70190e | Vendor (CNA) |
| azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 | — | Microsoft (MSRC) |
| azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 | 6.6.157.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.12.111-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.111-1~deb12u1 · Debian:12 | Package registry (OSV) |
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.
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 researchersFinders, 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.
No nightly-computed relations.
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1085 · Sep 14, 2026(Linux Kernel Güvenlik Bildirimi)
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
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/3a0b05145053a5fad1a2ddb4e4d87b07385e63e5
- git.kernel.org/stable/c/3b3d27670c0c890ba7cf1bc3614cab61bde6d25c
- git.kernel.org/stable/c/49a4dcf57608ebf6432dbcb203ed25e7ed581445
- git.kernel.org/stable/c/6efbc52237facda35d2d874fe1765bb4839275d8
- git.kernel.org/stable/c/a4c3c7310156493797c920b10d8648c07aa05403
- git.kernel.org/stable/c/bc4013c7cce58d46f792c8c87bc8c8318a70190e
Vendor advisories and official records. Exploit/PoC links are deliberately left out.