CVE-2026-68141: net/af_iucv: fix NULL deref in afiucv_hs_callback_syn()

mediumCVSS 5.5CVE-2026-68141

CSIRTS triage

vendor: Linux product: Linux Kernel Denial of service

What: A NULL pointer dereference occurs in afiucv_hs_callback_syn() when certain conditions are met during IUCV connection setup.
Who is affected: Linux systems configured for AF_IUCV (IBM mainframe inter-user communication) protocol handling.
Urgency: Medium severity with CVSS 5.5; NULL dereference causes kernel crash and denial of service.
Action: Apply Linux kernel patch adding NULL pointer validation in afiucv_hs_callback_syn().

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.5
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68141

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-681410.53% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-68141	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for net/af_iucv

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-68141: In the Linux kernel, the following vulnerability has been resolved: net/af_iucv: fix NULL dere…nvd · 2026-08-10