CVE-2026-22983

CVE-2026-22983 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: net: do not write to msg_get_inq in callee NULL pointer dereference fix. msg_get_inq is an input field from caller to callee. Don't set it in the callee, as the caller may not clear it on struct reuse. This is a kernel-internal variant of msghdr only, and the only user does reinitialize the field. So this is not critical for that reason. But it is more robust to avoid the write, and slightly simpler code. And it fixes a bug, see below. Callers set msg_get_inq to request the input queue length to be returned in msg_inq. This is equivalent to but independent from the SO_INQ request to return that same info as a cmsg (tp->recvmsg_inq). To reduce branching in the hot path the second also sets the msg_inq. That is WAI. This is a fix to commit 4d1442979e4a ("af_unix: don't post cmsg for SO_INQ unless explicitly asked for"), which fixed the inverse. Also avoid NULL pointer dereference in unix_stream_read_generic if state->msg is NULL and msg->msg_get_inq is written. A NULL state->msg can happen when splicing as of commit 2b514574f7e8 ("net: af_unix: implement splice for stream af_unix sockets"). Also collapse two branches using a bitwise or.

Frequently asked questions

What is CVE-2026-22983?
In the Linux kernel, the following vulnerability has been resolved: net: do not write to msg_get_inq in callee NULL pointer dereference fix. msg_get_inq is an input field from caller to callee. Don't set it in the callee, as the caller may not clear it on struct reuse. This is a kernel-internal variant of msghdr only, and the only user does reinitialize the field. So this is not critical for that reason. But it is more robust to avoid the write, and slightly simpler code. And it fixes a bug, see below. Callers set msg_get_inq to request the input queue length to be returned in msg_inq. This is equivalent to but independent from the SO_INQ request to return that same info as a cmsg (tp->recvmsg_inq). To reduce branching in the hot path the second also sets the msg_inq. That is WAI. This is a fix to commit 4d1442979e4a ("af_unix: don't post cmsg for SO_INQ unless explicitly asked for"), which fixed the inverse. Also avoid NULL pointer dereference in unix_stream_read_generic if state->msg is NULL and msg->msg_get_inq is written. A NULL state->msg can happen when splicing as of commit 2b514574f7e8 ("net: af_unix: implement splice for stream af_unix sockets"). Also collapse two branches using a bitwise or.
How severe is CVE-2026-22983?
CVE-2026-22983 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-22983 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-22983?
CVE-2026-22983 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-22983?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-22983 have an EU (EUVD) identifier?
Yes. CVE-2026-22983 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-4320.
When was CVE-2026-22983 published?
CVE-2026-22983 was published on 2026-01-23 and last updated on 2026-06-17.

References

Affected products (2)

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