CVE-2026-31638 rxrpc: Only put the call ref if one was acquired

What is CVE-2026-31638?

CVE-2026-31638 is a high-severity vulnerability in Linux kernel, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

rxrpc: Only put the call ref if one was acquired

rxrpc_input_packet_on_conn() can process a to-client packet after the current client call on the channel has already been torn down. In that case chan->call is NULL, rxrpc_try_get_call() returns NULL and there is no reference to drop.

The client-side implicit-end error path does not account for that and unconditionally calls rxrpc_put_call(). This turns a protocol error path into a kernel crash instead of rejecting the packet.

Only drop the call reference if one was actually acquired. Keep the existing protocol error handling unchanged.

Weakness: CWE-476

Which versions are affected by CVE-2026-31638?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-31638?

Apply the vendor's patch.

Is CVE-2026-31638 being exploited?

There is no known exploitation of CVE-2026-31638 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-83672, BELL-CVE-2026-31638, DEBIAN-CVE-2026-31638, GHSA-5vqj-w88j-2624, ROOT-OS-DEBIAN-13-CVE-2026-31638, ROOT-OS-UBUNTU-2404-CVE-2026-31638 and 1 more.