CVE-2026-64268: RDMA/siw: bound Read Response placement to the RREAD length
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: 0.71% (FIRST EPSS); higher than 53.9% of all records.
- 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 3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf, 423a78ff7928c2601013f73ec6d896f5597d0df5, 595e6537ad1a210da32cbb9a7f91aa73090915ba; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.
Low priority for now. Upgrade to Linux Linux 3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf, 423a78ff7928c2601013f73ec6d896f5597d0df5, 595e6537ad1a210da32cbb9a7f91aa73090915ba; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 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: RDMA/siw: bound Read Response placement to the RREAD length In drivers/infiniband/sw/siw/siw_qp_rx.c, siw_proc_rresp() places each inbound Read Response DDP segment at sge->laddr + wqe->processed and then accumulates wqe->processed, but it never checks the running total against the sink buffer length on continuation segments. siw_check_sge() resolves and validates the sink memory only on the first fragment (the if (!*mem) branch), and siw_rresp_check_ntoh() compares the cumulative length against wqe->bytes only on the final segment (the !frx->more_ddp_segs guard). A connected siw peer that answers an outstanding RREAD with Read Response segments that keep the DDP Last flag clear, carrying more total payload than the RREAD requested, drives wqe->processed past the validated sink buffer; the next siw_rx_data() call writes out of bounds at sge->laddr + wqe->processed. siw runs iWARP over ordinary routable TCP, so the peer is the remote end of an established RDMA connection and needs no local privilege. Bound every segment before placement, exactly as siw_proc_send() and siw_proc_write() already do for their tagged and untagged paths, and terminate the connection with a base-or-bounds DDP error when the Read Response would overrun the sink buffer. This is the second receive-path length fix for this file. A separate change rejects an MPA FPDU length that underflows the per-fragment remainder in the header decode; that guard does not cover this case, because here each individual segment length is self-consistent and only the accumulated placement offset overruns the buffer.
- Published
- Jul 25, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.7% · 53th percentile
- CWE
- CWE-787
Report tools
Action score
39
Monitor
Low priority for now.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.7%
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.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel5.3 and later · before 5.10.261
- linux linux kernel5.11 and later · before 5.15.212
- linux linux kernel5.16 and later · before 6.1.178
- linux linux kernel6.2 and later · before 6.6.145
- linux linux kernel6.7 and later · before 6.12.96
- linux linux kernel6.13 and later · before 6.18.39
- linux linux kernel6.19 and later · before 7.1.4
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
- 5.3affected
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before a31b6d18ded3cc32d9ee85a6ff0726d4274887b2affected · git
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before 595e6537ad1a210da32cbb9a7f91aa73090915baaffected · git
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before 3ef7e052cbd05a8b13a51a07b185a39ec93ee1cfaffected · git
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before b2e26c955f8dd7e8d3f16c858db05245ea4fa817affected · git
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before 6bc89f34a4597f9f6d41f7a60c67a3153bfe8851affected · git
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before 423a78ff7928c2601013f73ec6d896f5597d0df5affected · git
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before 75c93cd3c421890f49ea93f0b978b9b7bb10e5e3affected · git
- 8b6a361b8c482f22ac99c3273285ff16b23fba91 and later · before 7d29f7e9dbd844cae4d3e559cf78324b9642fd6baffected · git
- before 5.3not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | bpftool | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-abi-stablelists | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-core | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-cross-headers | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-debug | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-debug-core | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-debug-devel | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules-extra | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-devel | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-doc | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-headers | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-modules | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-modules-extra | before 4.18.0-553.159.1.el8_10 | 4.18.0-553.159.1.el8_10 |
| AlmaLinux:8 | kernel-rt | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-core | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-debug | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-core | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-devel | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules-extra | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-devel | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
| AlmaLinux:8 | kernel-rt-modules | before 4.18.0-553.159.1.rt7.500.el8_10 | 4.18.0-553.159.1.rt7.500.el8_10 |
+96
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2026-64256Jul 25, 2026 · xfs: don't wrap around quota ids in dqiterate22Monitor
- ← EarlierCVE-2026-64266Jul 25, 2026 · fuse: re-lock request before returning from fuse_ref_folio()31Monitor
- Later →CVE-2026-64270Jul 25, 2026 · Input: mms114 - reject an oversized device packet size31Monitor
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 | 3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf | Vendor (CNA) |
| Linux Linux | 423a78ff7928c2601013f73ec6d896f5597d0df5 | Vendor (CNA) |
| Linux Linux | 595e6537ad1a210da32cbb9a7f91aa73090915ba | Vendor (CNA) |
| Linux Linux | 6bc89f34a4597f9f6d41f7a60c67a3153bfe8851 | Vendor (CNA) |
| Linux Linux | 75c93cd3c421890f49ea93f0b978b9b7bb10e5e3 | Vendor (CNA) |
| Linux Linux | 7d29f7e9dbd844cae4d3e559cf78324b9642fd6b | Vendor (CNA) |
| Linux Linux | a31b6d18ded3cc32d9ee85a6ff0726d4274887b2 | Vendor (CNA) |
| Linux Linux | b2e26c955f8dd7e8d3f16c858db05245ea4fa817 | Vendor (CNA) |
| azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 | 6.6.145.2-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:bpftool | 4.18.0-553.159.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel | 4.18.0-553.159.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-core | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-core | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-devel | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-modules | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-modules-extra | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-devel | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-modules | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-modules-extra | 4.18.0-553.159.1.rt7.500.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| debian:linux | 6.1.180-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.100-1~deb12u1 · Debian:12 | Package registry (OSV) |
| red hat:kernel-rt | 0:4.18.0-553.159.1.rt7.500.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-core | 0:4.18.0-553.159.1.rt7.500.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug | 0:4.18.0-553.159.1.rt7.500.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-core | 0:4.18.0-553.159.1.rt7.500.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-debuginfo | 0:4.18.0-553.159.1.rt7.500.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-devel | 0:4.18.0-553.159.1.rt7.500.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-kvm | 0:4.18.0-553.159.1.rt7.500.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
+7
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).
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-787 · Out-of-bounds WriteCVSS 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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/423a78ff7928c2601013f73ec6d896f5597d0df5
- git.kernel.org/stable/c/595e6537ad1a210da32cbb9a7f91aa73090915ba
- git.kernel.org/stable/c/6bc89f34a4597f9f6d41f7a60c67a3153bfe8851
- git.kernel.org/stable/c/75c93cd3c421890f49ea93f0b978b9b7bb10e5e3
- git.kernel.org/stable/c/7d29f7e9dbd844cae4d3e559cf78324b9642fd6b
- git.kernel.org/stable/c/a31b6d18ded3cc32d9ee85a6ff0726d4274887b2
- git.kernel.org/stable/c/b2e26c955f8dd7e8d3f16c858db05245ea4fa817
Vendor advisories and official records. Exploit/PoC links are deliberately left out.