NVD / CVE Program· CNA Linux

CVE-2026-64563: rhashtable: clear stale iter->p on table restart

Noroxi assessment

Priority: Monitor (action score 31/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 042fda5c088015f18838e5c692659a7be60aeb26, 0955b65c2b47c30b439e2cf1b1e375073aa0413a, 3ff7c1dbf722cf3fa538672452ba182318e0fcc3; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 042fda5c088015f18838e5c692659a7be60aeb26, 0955b65c2b47c30b439e2cf1b1e375073aa0413a, 3ff7c1dbf722cf3fa538672452ba182318e0fcc3; azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 6.6.152.1-1 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: rhashtable: clear stale iter->p on table restart rhashtable_walk_start_check() has two restart paths when resuming a walk. When iter->walker.tbl is valid, it re-validates iter->p against the table and sets iter->p = NULL if the object is gone. When iter->walker.tbl is NULL (table was freed during resize), it resets slot and skip but forgets to clear iter->p. rhashtable_walk_next() then dereferences the stale iter->p, reading freed memory. This is a use-after-free. Any caller that does multi-fragment rhashtable walks across walk_stop/walk_start boundaries is affected. Concrete cases include netlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC (tipc_nl_sk_walk in net/tipc/socket.c). Crash stack (netlink_diag): BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0 Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080) Call Trace: rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016) __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122) netlink_diag_dump+0xc2/0x240 netlink_dump+0x5bc/0x1270 netlink_recvmsg+0x7a3/0x980 sock_recvmsg+0x1bc/0x200 __sys_recvfrom+0x1d4/0x2c0

HighCVSS 7.8 · v3.1—Proof of concept Fix available

Memory safety

Published: Aug 4, 2026
Updated: Oct 19, 2026
EPSS: 0.1% · 5th percentile
CWE: CWE-416

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 7.8; 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
Proof of concept exists, no weaponized module
A fix has been released

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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.

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Affected 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.

—

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
- 4.18affected
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before ba510b5e9fe396497d31162acb579f210adfe6c8affected · git
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before a0406c40c6638c5ae50257db6297b2fba6c9ba16affected · git
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before 0955b65c2b47c30b439e2cf1b1e375073aa0413aaffected · git
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before c39643ad99fea749be50615550e8f0e6d6e60694affected · git
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before 042fda5c088015f18838e5c692659a7be60aeb26affected · git
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before 3ff7c1dbf722cf3fa538672452ba182318e0fcc3affected · git
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before 4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3affected · git
- 5d240a8936f6a1d3ece06701e8c4d830a2eca8a8 and later · before 8173f7e2ce67e6ca1d4763f3da14e5b01ce77456affected · git
- before 4.18not 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 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-abi-stablelists	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-core	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-cross-headers	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-debug	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-debug-core	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-debug-devel	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-debug-modules	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-debug-modules-extra	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-devel	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-doc	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-headers	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-modules	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-modules-extra	before 4.18.0-553.160.1.el8_10	4.18.0-553.160.1.el8_10
AlmaLinux:8	kernel-rt	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-core	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-debug	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-debug-core	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-debug-devel	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-debug-modules	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-debug-modules-extra	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-devel	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10
AlmaLinux:8	kernel-rt-modules	before 4.18.0-553.160.1.rt7.501.el8_10	4.18.0-553.160.1.rt7.501.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
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CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
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CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
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Published before and after this one in the same product

← EarlierCVE-2026-64561Aug 4, 2026 · KVM: x86: Check for invalid/obsolete root *after* making MMU pages available
35Monitor
← EarlierCVE-2026-64562Aug 4, 2026 · KVM: nVMX: Hide shadow VMCS right after VMCLEAR
35Monitor
Later →CVE-2026-64564Aug 4, 2026 · sctp: don't free the ASCONF's own transport in DEL-IP processing
39Monitor

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	042fda5c088015f18838e5c692659a7be60aeb26	Vendor (CNA)
Linux Linux	0955b65c2b47c30b439e2cf1b1e375073aa0413a	Vendor (CNA)
Linux Linux	3ff7c1dbf722cf3fa538672452ba182318e0fcc3	Vendor (CNA)
Linux Linux	4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3	Vendor (CNA)
Linux Linux	8173f7e2ce67e6ca1d4763f3da14e5b01ce77456	Vendor (CNA)
Linux Linux	a0406c40c6638c5ae50257db6297b2fba6c9ba16	Vendor (CNA)
Linux Linux	ba510b5e9fe396497d31162acb579f210adfe6c8	Vendor (CNA)
Linux Linux	c39643ad99fea749be50615550e8f0e6d6e60694	Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0	6.6.152.1-1 · Release Notes	Microsoft (MSRC)
almalinux:bpftool	4.18.0-553.160.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel	4.18.0-553.160.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-core	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-core	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-devel	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-modules	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-modules-extra	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-devel	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-modules	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-modules-extra	4.18.0-553.160.1.rt7.501.el8_10 · AlmaLinux:8	Package registry (OSV)
debian:linux	6.1.187-1 · Debian:12	Package registry (OSV)
debian:linux-6.12	6.12.101-1~deb12u1 · Debian:12	Package registry (OSV)
red hat:kernel-rt	0:4.18.0-553.160.1.rt7.501.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-core	0:4.18.0-553.160.1.rt7.501.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug	0:4.18.0-553.160.1.rt7.501.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug-core	0:4.18.0-553.160.1.rt7.501.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug-debuginfo	0:4.18.0-553.160.1.rt7.501.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug-devel	0:4.18.0-553.160.1.rt7.501.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug-kvm	0:4.18.0-553.160.1.rt7.501.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:0	2026-08-12

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.

PublishedAug 4, 2026
First PoCAug 12, 2026+8 d
TodayOct 30, 2026+87 d

EPSS, last 120 days

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 researchers

Finders, 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.

CVE-2026-645640 days apartsctp: don't free the ASCONF's own transport in DEL-IP processing
39Monitor
CVE-2026-681176 days aparttipc: clear sock->sk on the failed-insert path in tipc_sk_create()
39Monitor
CVE-2026-681446 days apartphonet: pep: fix use-after-free in pep_get_sb()
39Monitor
CVE-2026-681566 days apartlibceph: refresh auth->authorizer_buf{,_len} after authorizer update
39Monitor
CVE-2026-683816 days apartksmbd: pin conn during async oplock break notification
39Monitor
CVE-2026-684266 days apartxfrm: fix stale skb->prev after async crypto steals a GSO segment
39Monitor

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-26-0742 · Aug 5, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
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: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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— → noneOct 16, 2026, 5:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:07 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/042fda5c088015f18838e5c692659a7be60aeb26

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records

Noroxi analysis

What does it mean in your environment?

We use this product, ask for help

Data sources and verification

CNA: Linux

CVE.org (CNA)Oct 19, 2026, 8:48 PM UTC
CISA ADPOct 19, 2026, 8:48 PM UTC
NVDOct 19, 2026, 9:17 PM UTC
FIRST EPSSOct 29, 2026, 12:00 AM UTC
OSV / GHSAOct 30, 2026, 3:18 AM UTC
MSRCOct 29, 2026, 3:24 AM UTC
PoC-in-GitHubOct 30, 2026, 3:18 AM UTC

Each line is when that source was last processed for this record.