CVE-2026-43011
Linux Kernel double free
- Published1 May 2026
Description
In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix potential double free of skb When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain: x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again This would free the same skb twice. Looking at x25_backlog_rcv: net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); }
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
- https://git.kernel.org/stable/c/143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1
- https://git.kernel.org/stable/c/3f5e3005984645bf5bd129c6b13149879580b1fb
- https://git.kernel.org/stable/c/524371398d8463ea7e101fce2cbf3915645d1730
- https://git.kernel.org/stable/c/5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9
- https://git.kernel.org/stable/c/c87dd137c0dad07cc55f98181ff380b0c23d2878
- https://git.kernel.org/stable/c/d10a26aa4d072320530e6968ef945c8c575edf61
References
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://git.kernel.org/stable/c/143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1
- https://git.kernel.org/stable/c/3f5e3005984645bf5bd129c6b13149879580b1fb
- https://git.kernel.org/stable/c/524371398d8463ea7e101fce2cbf3915645d1730
- https://git.kernel.org/stable/c/5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9
- https://git.kernel.org/stable/c/c87dd137c0dad07cc55f98181ff380b0c23d2878
- https://git.kernel.org/stable/c/d10a26aa4d072320530e6968ef945c8c575edf61
- https://git.kernel.org/stable/c/f782dd382203b2a8c4552a628431b7de65a19a7b
- https://git.kernel.org/stable/c/fa1dbc93530b34fab0da9862426fe9c918c74dc0
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-43011 being actively exploited?
CVE-2026-43011 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.87%.
How severe is CVE-2026-43011?
CVE-2026-43011 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.87% probability of exploitation.
Which products are affected by CVE-2026-43011?
Affected products include Linux Kernel.
How do I fix CVE-2026-43011?
Upgrade affected software to a fixed version, for example Linux Kernel 5.10.253 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-43011 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.