High

CVE-2026-68397 — net/iucv: take a reference on the socket found in afiucv_hs_rcv()

In the Linux kernel, the following vulnerability has been resolved: net/iucv: take a reference on the socket found in afiucv_hs_rcv() afiucv_hs_rcv() looks up the destination socket under iucv_sk_list.lock, drops the lock, and then passes the socket to the afiucv_hs_callback_*() handlers without holding a reference. AF_IUCV sockets are not RCU-protected and are freed synchronously by iucv_sock_kill() -> sock_put(), so a concurrent close can free the socket in the window between read_unlock() and the handler, which then dereferences freed memory (for example sk->sk_data_ready() in afiucv_hs_callback_syn()). Take a reference with sock_hold() while the socket is still on the list and release it with sock_put() once the handler has run.

Published Aug 10, 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

8.8

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	≥ 3881ac441f642d56503818123446f7298442236b and < 5739be5c19495d709d902a2912c9102ce78740d5≥ 3881ac441f642d56503818123446f7298442236b and < bc6c6e546ffff8865daaeb622ef348c2d481e80f≥ 3881ac441f642d56503818123446f7298442236b and < e3e0679fc950191aff8f27fa78abcfc2462cff4a≥ 3881ac441f642d56503818123446f7298442236b and < 4dc0e63abf8bc7ba8892e617c1fb8b204361e022≥ 3881ac441f642d56503818123446f7298442236b and < 1801cb20a5025a787d6853e19c38db138344b4b4≥ 3881ac441f642d56503818123446f7298442236b and < c75a950e77356e526672cba4584080c6c8b793b6≥ 3881ac441f642d56503818123446f7298442236b and < 5595ea59cdf29182cf6a270cacc1426c57b603de≥ 3881ac441f642d56503818123446f7298442236b and < 4fa349156043dc119721d067329714179f501749 and 1 more version 3.2	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

Adjacent

Attack complexity

Low

Privileges required

None

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
8.8	CVSS 3.1	High	2.8	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.8	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:A/AC:L/PR:N/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.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

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 · 8.8
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 10, 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/5595ea59cdf29182cf6a270cacc1426c57b603de
NIST National Vulnerability Database
git.kernel.org/stable/c/4fa349156043dc119721d067329714179f501749
NIST National Vulnerability Database
git.kernel.org/stable/c/5739be5c19495d709d902a2912c9102ce78740d5
NIST National Vulnerability Database
git.kernel.org/stable/c/e3e0679fc950191aff8f27fa78abcfc2462cff4a
NIST National Vulnerability Database
git.kernel.org/stable/c/4dc0e63abf8bc7ba8892e617c1fb8b204361e022
NIST National Vulnerability Database
git.kernel.org/stable/c/c75a950e77356e526672cba4584080c6c8b793b6
NIST National Vulnerability Database
git.kernel.org/stable/c/1801cb20a5025a787d6853e19c38db138344b4b4
NIST National Vulnerability Database
git.kernel.org/stable/c/bc6c6e546ffff8865daaeb622ef348c2d481e80f
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 13h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
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-2026-68397 is "net/iucv: take a reference on the socket found in afiucv_hs_rcv()", 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 8.8 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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