critical CVSS 9.3

CVE-2026-64080·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_ffa: Snapshot notifier callbacks under lock Both notification handlers currently look up a notifier callback under notify_lock, drop the lock, and then dereference the returned notifier entry. A concurrent unregister can delete and free that entry in the gap, leaving the handler to dereference stale memory. Copy the callback pointer and callback data while notify_lock is still held and invoke the callback only after the lock is dropped. This keeps the existing callback execution model while removing the use-after-free window in both the framework and non-framework notification paths.

Severity
critical
Software
Kernel
Fixed in
7.0.11
Published
2026-07-19

Affected versions

From: 6.19

Until: 7.0.11

Fixed in: 7.0.11

How to fix this CVE

Update your Linux kernel to version 7.0.11 or later to patch a critical use-after-free vulnerability in the ARM FFA firmware notification handler. This vulnerability allows local attackers to trigger memory corruption through race conditions in the notification callback mechanism. Verify your kernel version and apply the update immediately through your distribution's package manager.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check current kernel version: uname -r
  2. Verify if ARM FFA firmware is in use: grep -i ffa /boot/config-$(uname -r) or cat /proc/cmdline | grep -i ffa
  3. Search kernel logs for notification handler errors: journalctl -k | grep -i 'ffa\|notif\|use-after-free'
  4. Confirm patch applied: grep 'CONFIG_ARM_FFA' /boot/config-$(uname -r) and verify kernel version is 7.0.11 or higher with uname -r

FAQ

What is CVE-2026-64080?

This is a critical use-after-free vulnerability in the Linux kernel's ARM FFA (Firmware Framework for Arm A-profile) notification handler. An attacker can trigger a race condition that causes the kernel to dereference freed memory when unregistering notification callbacks, leading to kernel panic or arbitrary code execution.

Is CVE-2026-64080 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. However, the critical severity warrants immediate patching.

What versions of Kernel are affected by CVE-2026-64080?

Linux kernel versions from 6.19 through 7.0.10 are vulnerable. Version 7.0.11 and later include the fix.

How do I check if my server is vulnerable to CVE-2026-64080?

Run 'uname -r' and check if your kernel version is between 6.19 and 7.0.10 inclusive. If so, you are vulnerable. Additionally, verify ARM FFA is enabled with 'grep CONFIG_ARM_FFA /boot/config-$(uname -r)'.

Does Defensia detect CVE-2026-64080?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2026-64080 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2026-100075CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/srpt: Fix srpt_alloc_rw_ctxs() unwind counters When srpt_alloc_rw_ctxs() fails partway through a multi-buffer indirect descriptor, the unwind path destroys RDMA contexts but leaves stale n_rw_ctx and n_rdma values (and a dangling rw_ctxs pointer). Later sq_wr_avail accounting in srpt_queue_response() or srpt_write_pending() can then subtract the wrong number of send queue credits. Reset the counters and clear rw_ctxs after freeing the heap allocation before returning an error.
CVE-2026-64397CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERY_DIRECTORY requests per file smb2_query_dir() stores a pointer to its stack-allocated private data in the ksmbd_file readdir_data. Concurrent QUERY_DIRECTORY requests using the same file handle can overwrite this pointer while an iterate_dir() callback is still using it, resulting in a stack use-after-free. Add a per-file mutex and hold it while accessing the shared directory enumeration state. The lock covers scan restart, dot entry state, readdir_data setup and iteration, and response construction. This prevents another request from replacing readdir_data.private before the current request has finished using it and also serializes the shared file position.
CVE-2026-64399CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE The FSCTL_DUPLICATE_EXTENTS_TO_FILE arm of smb2_ioctl() overwrites the destination file's data via vfs_clone_file_range() with neither the share-level KSMBD_TREE_CONN_FLAG_WRITABLE check nor a per-handle fp->daccess check that the other write-bearing arms carry. A client can overwrite destination data on a read-only share, or from a handle opened with only FILE_WRITE_ATTRIBUTES (which still yields an FMODE_WRITE filp). FILE_WRITE_ATTRIBUTES-only destination handle overwrote the file's data via the clone. Add both checks, matching the FSCTL_SET_SPARSE permission fix; require FILE_WRITE_DATA since this writes data.
CVE-2026-64046CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: net: tls: prevent chain-after-chain in plain text SG Sashiko points out that if end = 0 (start != 0) the current code will create a chain link to content type right after the wrap link: This would create a chain where the wrap link points directly to another chain link. The scatterlist API sg_next iterator does not recursively resolve consecutive chain links. meaning this is illegal input to crypto. The wrapping link is unnecessary if end = 0. end is the entry after the last one used so end = 0 means there's nothing pushed after the wrap: end start i v v v [ ]...[ ][ d ][ d ][ d ][ d ][rsv for wrap] Skip the wrapping in this case. TLS 1.3 can use the "wrapping slot" for it's chaining if end = 0. This avoids the chain-after-chain. Move the wrap chaining before marking END and chaining off content type, that feels like more logical ordering to me, but should not matter from functional perspective.
CVE-2026-52924CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: sctp: purge outqueue on stale COOKIE-ECHO handling sctp_stream_update() is only invoked when the association is moved into COOKIE_WAIT during association setup/reconfiguration. In this path, the outbound stream scheduler state (stream->out_curr) is expected to be clean, since no user data should have been transmitted yet unless the state machine has already partially progressed. However, a corner case exists in sctp_sf_do_5_2_6_stale(): when a Stale Cookie ERROR is received, the association is rolled back from COOKIE_ECHOED to COOKIE_WAIT. In this scenario, user data may already have been queued and even bundled with the COOKIE-ECHO chunk. During the rollback, sctp_stream_update() frees the old stream table and installs a new one, but it does not invalidate stream->out_curr. As a result, out_curr may still point to a freed sctp_stream_out entry from the previous stream state. Later, SCTP scheduler dequeue paths (FCFS, RR, PRIO, etc.) rely on stream->out_curr->ext, which can lead to use-after-free once the old stream state has been released via sctp_stream_free(). This results in crashes such as (reported by Yuqi): BUG: KASAN: slab-use-after-free in sctp_sched_fcfs_dequeue+0x13a/0x140 Read of size 8 at addr ff1100004d4d3208 by task mini_poc/9312 CPU: 1 UID: 1001 PID: 9312 Comm: mini_poc Not tainted 7.1.0-rc1-00305-gbd3a4795d574 #5 PREEMPT(full) sctp_sched_fcfs_dequeue+0x13a/0x140 sctp_outq_flush+0x1603/0x33e0 sctp_do_sm+0x31c9/0x5d30 sctp_assoc_bh_rcv+0x392/0x6f0 sctp_inq_push+0x1db/0x270 sctp_rcv+0x138d/0x3c10 Fix this by fully purging the association outqueue when handling the Stale Cookie case. This ensures all pending transmit and retransmit state is dropped, and any scheduler cached pointers are invalidated, making it safe to rebuild stream state during COOKIE_WAIT restart. Updating only stream->out_curr would be insufficient, since queued and retransmittable data would still reference the old stream state and trigger later use-after-free in dequeue paths.

References

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