# CVE-2026-31638: rxrpc: Only put the call ref if one was acquired CVE-2026-31638 is fixed in 36 products on 1 platform, first by DEBIAN-CVE-2026-31638, released May 15, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-31638 - Priority: High - CVSS: 7.5 (Moderate) - EPSS: 0.0044 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Apr 24, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-31638 ## 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-uek ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-doc ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-doc ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-tools ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek-tools ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-204.92.4.2.el9uek | [ELSA-2026-50372](https://patchblox.com/security/data/fix/linux/elsa-2026-50372.md) | Jul 2, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.85-1 | [DEBIAN-CVE-2026-31638](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31638.md) | May 15, 2026 | | Linux | linux Debian 14 | 6.19.13-1 | [DEBIAN-CVE-2026-31638](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31638.md) | May 15, 2026 | --- Data as of 2026-11-09T07:25:28Z UTC. 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