High

CVE-2026-72126 — can: isotp: use unconditional synchronize_rcu() in isotp_release()

In the Linux kernel, the following vulnerability has been resolved: can: isotp: use unconditional synchronize_rcu() in isotp_release() isotp_notify() unregisters the (RCU) CAN filters via can_rx_unregister() and clears so->bound without waiting for a grace period. isotp_release() uses so->bound to decide whether it needs to call synchronize_rcu() before cancelling so->rxtimer, so when NETDEV_UNREGISTER runs first it skips that synchronize_rcu() and can cancel the timer while an in-flight isotp_rcv() is still executing and about to re-arm it via isotp_send_fc(), leading to a use-after-free timer callback on the freed socket. sakisho-bot remarked a problem with rtnl_lock held in isotp_notify(), therefore make isotp_release() always call synchronize_rcu() before cancelling the timers, regardless of so->bound. This still closes the original race (isotp_notify() clearing so->bound without waiting for in-flight isotp_rcv() callers before isotp_release() cancels the RX timer) without adding any RCU wait to the netdevice notifier path.

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

Low

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

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

—

No EPSS score.

Affects

Linux

CVSS base

7.8

High · 2 source(s)

Remediation

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

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

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.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 22bfa94db2ef6900c790884fa9461486516626e9 and < 945d9894502cd9124f5d676181c542ed2000f7c0≥ 14a4696bc3118ba49da28f79280e1d55603aa737 and < 59672aa4bcd8d32172c1ff6a179583981d6acabc≥ 14a4696bc3118ba49da28f79280e1d55603aa737 and < 15413a082df69175c2f96aeab4c26fe1ff7cff03≥ 14a4696bc3118ba49da28f79280e1d55603aa737 and < 6280eda96e0707264849fa7d036fed873c1f8a6d≥ 14a4696bc3118ba49da28f79280e1d55603aa737 and < cb6abc584a1bfab107ac003d64948a4aef1730aa≥ 14a4696bc3118ba49da28f79280e1d55603aa737 and < b88a511308779c225005d7994b8744561bdbafbc≥ 14a4696bc3118ba49da28f79280e1d55603aa737 and < b8278ff605187ef3fa0f2705e93251cce4c4f8ee≥ 14a4696bc3118ba49da28f79280e1d55603aa737 and < 9b1a02e0d980ac6b0e36a90378f847062f81d7e4 and 6 more version 80c6ddf771df2ef786f28c1ca5919b3f1080091bversion ebf91625b3e404bd2b4b694c7ee71c1e8f8bd08f≥ 5.10.50 and < 5.10.261≥ 5.12.17 and < 5.13≥ 5.13.2 and < 5.14version 5.14	Vulnerable	CVE Program (cve.org) e CISA ADP

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.

Score	Version	Severity	Expl.	Impact	Scored 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	—	—	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)

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.

endpoint telemetry (EDR)

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
CVSS changed · 7.8
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Aug 15, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

git.kernel.org/stable/c/b88a511308779c225005d7994b8744561bdbafbc
NIST National Vulnerability Database
git.kernel.org/stable/c/15413a082df69175c2f96aeab4c26fe1ff7cff03
NIST National Vulnerability Database
git.kernel.org/stable/c/945d9894502cd9124f5d676181c542ed2000f7c0
NIST National Vulnerability Database
git.kernel.org/stable/c/cb6abc584a1bfab107ac003d64948a4aef1730aa
NIST National Vulnerability Database
git.kernel.org/stable/c/6280eda96e0707264849fa7d036fed873c1f8a6d
NIST National Vulnerability Database
git.kernel.org/stable/c/9b1a02e0d980ac6b0e36a90378f847062f81d7e4
NIST National Vulnerability Database
git.kernel.org/stable/c/59672aa4bcd8d32172c1ff6a179583981d6acabc
NIST National Vulnerability Database
git.kernel.org/stable/c/b8278ff605187ef3fa0f2705e93251cce4c4f8ee
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown 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 FIRST EPSS score.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
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-2026-72126 is "can: isotp: use unconditional synchronize_rcu() in isotp_release()", 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. 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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