# CVE-2026-31638

> Vulnerability · severity: **HIGH** (CVSS 7.5).

## 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.

## Key facts

- **CVE ID:** CVE-2026-31638
- **Published:** 2026-04-24
- **CVSS severity:** HIGH
- **CVSS base score:** 7.5
- **CWE codes:** CWE-476

## Affected products

- `linux:linux_kernel`

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31638

## Citation

> AI Analytics. CVE-2026-31638. Retrieved 2026-08-11 from https://api.ai-analytics.org/cve/CVE-2026-31638. Derived from NIST NVD. Licensed CC0.

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