In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix potential UAF after skb_unshare() failure If skb_unshare() fails to… (CVE-2026-45998)
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix potential UAF after skb_unshare() failure If skb_unshare() fails to unshare a packet due to allocation failure in rxrpc_input_packet(), the skb pointer in the parent (rxrpc_io_thread()) will be NULL'd out. This will likely cause the call to trace_rxrpc_rx_done() to oops. Fix this by moving the unsharing down to where rxrpc_input_call_event() calls rxrpc_input_call_packet(). There are a number of places prior to that where we ignore DATA packets for a variety of reasons (such as the call already being complete) for which an unshare is then avoided. And with that, rxrpc_input_packet() doesn't need to take a pointer to the pointer to the packet, so change that to just a pointer.
AI Analysis
Technical Summary
CVE-2026-45998 is a vulnerability in the Linux kernel's rxrpc networking code where a failure in skb_unshare() during packet processing can cause the skb pointer in the parent context to be NULL'd out. This leads to a potential use-after-free condition and a kernel oops when trace_rxrpc_rx_done() is called. The fix involves moving the unsharing operation to a later stage in the packet processing pipeline to avoid unsharing packets that are ignored for various reasons, eliminating the need for passing a pointer to a pointer and preventing the NULL pointer dereference.
Potential Impact
Successful exploitation can cause a kernel oops (crash) due to a NULL pointer dereference in the rxrpc subsystem. This impacts system stability and availability. The CVSS vector indicates high impact on confidentiality, integrity, and availability (C:H/I:H/A:H), but no known exploits are reported in the wild.
Mitigation Recommendations
A security update fixing this vulnerability is available from Red Hat as part of their kernel update for Red Hat Enterprise Linux 10. Users should apply the official kernel update (e.g., kernel-6.12.0-211.30.1.el10_2 or later) and reboot the system to fully remediate the issue. Patch status is confirmed by the Red Hat advisory. No additional mitigations are required beyond applying the official fix.
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix potential UAF after skb_unshare() failure If skb_unshare() fails to… (CVE-2026-45998)
Description
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix potential UAF after skb_unshare() failure If skb_unshare() fails to unshare a packet due to allocation failure in rxrpc_input_packet(), the skb pointer in the parent (rxrpc_io_thread()) will be NULL'd out. This will likely cause the call to trace_rxrpc_rx_done() to oops. Fix this by moving the unsharing down to where rxrpc_input_call_event() calls rxrpc_input_call_packet(). There are a number of places prior to that where we ignore DATA packets for a variety of reasons (such as the call already being complete) for which an unshare is then avoided. And with that, rxrpc_input_packet() doesn't need to take a pointer to the pointer to the packet, so change that to just a pointer.
CVSS v3.1
Score 7.8high
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-45998 is a vulnerability in the Linux kernel's rxrpc networking code where a failure in skb_unshare() during packet processing can cause the skb pointer in the parent context to be NULL'd out. This leads to a potential use-after-free condition and a kernel oops when trace_rxrpc_rx_done() is called. The fix involves moving the unsharing operation to a later stage in the packet processing pipeline to avoid unsharing packets that are ignored for various reasons, eliminating the need for passing a pointer to a pointer and preventing the NULL pointer dereference.
Potential Impact
Successful exploitation can cause a kernel oops (crash) due to a NULL pointer dereference in the rxrpc subsystem. This impacts system stability and availability. The CVSS vector indicates high impact on confidentiality, integrity, and availability (C:H/I:H/A:H), but no known exploits are reported in the wild.
Mitigation Recommendations
A security update fixing this vulnerability is available from Red Hat as part of their kernel update for Red Hat Enterprise Linux 10. Users should apply the official kernel update (e.g., kernel-6.12.0-211.30.1.el10_2 or later) and reboot the system to fully remediate the issue. Patch status is confirmed by the Red Hat advisory. No additional mitigations are required beyond applying the official fix.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_vex
- Csaf Version
- 2.0
- Publisher
- Microsoft Security Response Center
- Advisory Id
- msrc_CVE-2026-45998
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- 3.1
Threat ID: 6a18ab78e29bf47b50288d27
Added to database: 05/28/2026, 20:54:16 UTC
Last enriched: 07/04/2026, 00:48:22 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 78
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