CVE-2026-64268: In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: bound Read Response placement t

Q: How do I fix CVE-2026-64268?

linux kernel: upgrade to 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-64268 being exploited?

CVE-2026-64268 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-64268 affect?

CVE-2026-64268 affects linux kernel. Severity is critical (CVSS 9.8). 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 sg

Q: How urgent is CVE-2026-64268?

Priority 61/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-64268 is a critical-severity flaw (CVSS 9.8) affecting linux kernel. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 memo

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-787
Published	2026-07-25
Last modified	2026-10-19

Publisher (CNA): kernel.org · Vendor: linux

Last updated 2026-10-19 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-25 10:17 UTCPublished CVE record published
2026-10-19 21:17 UTCUpdated Record last modified

linux linux kernel UPGRADE

Affected: >= 5.3 and < 5.10.261 · >= 5.11 and < 5.15.212 · >= 5.16 and < 6.1.178 · >= 6.2 and < 6.6.145 · >= 6.7 and < 6.12.96 · >= 6.13 and < 6.18.39 · >= 6.19 and < 7.1.4

Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

Fedora 46 · gcl · FIXED · 2.7.1-12.fc46 · FEDORA-2026-ff383a759b · source

sudo dnf upgrade --advisory=FEDORA-2026-ff383a759b

Fedora ELN · mozjs140 · FIXED · 140.13.0-5.eln159 · FEDORA-2026-f7ed0026e0 · source

sudo dnf upgrade --advisory=FEDORA-2026-f7ed0026e0

Ubuntu 20.04 · linux · NO FIX YET

Ubuntu 22.04 · linux · FIXED · 5.15.0-198.208

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "5.15.0-198.208" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · linux · FIXED · 6.8.0-147.147

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.8.0-147.147" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 20.04 · linux-hwe-5.15 · FIXED · 5.15.0-198.208~20.04.1

sudo apt update && sudo apt install --only-upgrade linux-hwe-5.15 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux-hwe-5.15)" ge "5.15.0-198.208~20.04.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · linux-hwe-6.8 · NO FIX YET

Debian 12 · linux · FIXED · 6.1.180-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.1.180-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · linux · FIXED · 6.12.96-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.12.96-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · linux-6.12 · FIXED · 6.12.100-1~deb12u1

sudo apt update && sudo apt install --only-upgrade linux-6.12 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux-6.12)" ge "6.12.100-1~deb12u1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 8 · kernel-rt · FIXED · kernel-rt-4.18.0-553.159.1.rt7.500.el8_10

sudo dnf upgrade --advisory=RHSA-2026:63013 rpm -q kernel-rt

RHEL 8 · kernel · FIXED · kernel-4.18.0-553.159.1.el8_10

sudo dnf upgrade --advisory=RHSA-2026:63014 rpm -q kernel

RHEL 8.4 Advanced Mission Critical Update Support · kernel · FIXED · kernel-4.18.0-305.206.1.el8_4

sudo dnf upgrade --advisory=RHSA-2026:65710 rpm -q kernel

RHEL 8.4 Extended Update Support Long-Life Add-On · kernel · FIXED · kernel-4.18.0-305.206.1.el8_4

sudo dnf upgrade --advisory=RHSA-2026:65710 rpm -q kernel

RHEL 8.6 Advanced Mission Critical Update Support · kernel · FIXED · kernel-4.18.0-372.216.1.el8_6

sudo dnf upgrade --advisory=RHSA-2026:69906 rpm -q kernel

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-64268?

linux kernel: upgrade to 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4. Exact commands for each OS are on this page.

Is CVE-2026-64268 being exploited?

CVE-2026-64268 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-64268 affect?

CVE-2026-64268 affects linux kernel. Severity is critical (CVSS 9.8). 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 sg

How urgent is CVE-2026-64268?

Priority 61/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

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References

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