CVE Intelligence
High Memory corruption

CVE-2026-64123 — net: hsr: defer node table free until after RCU readers

In the Linux kernel, the following vulnerability has been resolved: net: hsr: defer node table free until after RCU readers HSR node-list and node-status generic-netlink operations run under rcu_read_lock(). They walk hsr->node_db through hsr_get_next_node() and hsr_get_node_data(), but RTM_DELLINK teardown removes the same node table with plain list_del() and frees each node immediately. That lets a generic-netlink reader hold a struct hsr_node pointer across hsr_dellink(). In a KASAN build, widening the reader window after hsr_get_next_node() obtains the node reproduces a slab-use-after-free when the reader copies node->macaddress_A; the freeing stack is hsr_del_nodes() from hsr_dellink(). Use list_del_rcu() and defer the free through the existing hsr_free_node_rcu() callback. This matches the lifetime rule used by the HSR prune paths, which already delete nodes with list_del_rcu() and call_rcu().

Published Jul 19, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.1% (30-day exploitation probability)+0
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.13%
ahead of 2% of scored CVEs · Oct 15, 2026
Affects
Linux
Linux and 1 more
CVSS base
7.8
High · 3 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < 0ea70fb46940620848c08d9d399455c9e82fecdbversion 5.3≥ 5.2.12 and < 5.3version 08523d5a2f4a9e4202e00d282c164d453cabe2d2≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < aaec7096f9961eb223b5b149abe9495525c205d9≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < 8c3af18bb0d7c921a5219194037509463eb2ffde≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < 48d09dea506de667eb55f939bf98eec721effbdb≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < 6324423a8e6591f41a16c09a8f9a84e554ac147c
and 3 more ≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < 7713f4aafb577ff49fa67f0488d9c7dddc64d6ce≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < c5580114e0492bcd2e0a37613ed4c311e3fa3d4d≥ b9a1e627405d68d475a3c1f35e685ccfb5bbe668 and < 8be6685cdd1255bcc85f9b59e4bfc313aefc5c1b
Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel ≥ 5.2.12 and < 5.10.259version 7.1-rc4version 7.1-rc3version 7.1-rc2version 7.1-rc1≥ 6.13 and < 7.0.11≥ 6.7 and < 6.12.93≥ 6.2 and < 6.6.143
and 2 more ≥ 5.16 and < 6.1.176≥ 5.11 and < 5.15.210
Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.8 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-416 · Use After Free

Other CVEs with this weakness →

EPSS over time FIRST

Oct 14, 2026 → Oct 15, 2026 · 2 reading(s) · max 0.13%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • Fix documented
    Oct 15, 2026 · NIST National Vulnerability Database
  • Affected products added · linux/linux kernel
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVSS changed · 7.8
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · Alertas do Telegram
  • CVE published
    Jul 19, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 15, 2026 – Oct 15, 2026
  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

10 on the record

Elsewhere on this site

Linux
every CVE for this vendor
Memory corruption
same class
CWE-416
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 15h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 15h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No CISA SSVC assessment.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-64123 is "net: hsr: defer node table free until after RCU readers", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.13% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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