Amazon Linux 2023 Security Advisory: ALAS2023-2026-2032
Advisory Released Date: 2026-08-04
Advisory Updated Date: 2026-08-06
FAQs regarding Amazon Linux ALAS/CVE Severity
In the Linux kernel, the following vulnerability has been resolved:
ipv6: use RCU in ip6_output() (CVE-2025-40158)
In the Linux kernel, the following vulnerability has been resolved:
xfrm: Wait for RCU readers during policy netns exit (CVE-2026-43091)
In the Linux kernel, the following vulnerability has been resolved:
net/sched: fix pedit partial COW leading to page cache corruption (CVE-2026-46331)
In the Linux kernel, the following vulnerability has been resolved:
ip6_vti: set netns_immutable on the fallback device. (CVE-2026-52909)
In the Linux kernel, the following vulnerability has been resolved:
af_unix: Reject SIOCATMARK on non-stream sockets (CVE-2026-52928)
In the Linux kernel, the following vulnerability has been resolved:
sched/psi: fix race between file release and pressure write (CVE-2026-52991)
In the Linux kernel, the following vulnerability has been resolved:
fuse: limit FUSE_NOTIFY_RETRIEVE to uptodate folios (CVE-2026-53167)
In the Linux kernel, the following vulnerability has been resolved:
af_unix: Set gc_in_progress to true in unix_gc(). (CVE-2026-53361)
In the Linux kernel, the following vulnerability has been resolved:
virtiofs: fix UAF on submount umount
iput() called from fuse_release_end() can Oops if the super block has
already been destroyed. Normally this is prevented by waiting for
num_waiting to go down to zero before commencing with super block shutdown.
This only works, however, for the last submount instance, as the wait
counter is per connection, not per superblock.
Revert to using synchronous release requests for the auto_submounts case,
which is virtiofs only at this time. (CVE-2026-53381)
In the Linux kernel, the following vulnerability has been resolved:
vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write
A KASAN null-ptr-deref was observed in vcs_notifier():
BUG: KASAN: null-ptr-deref in vcs_notifier+0x98/0x130
Read of size 2 at addr qmp_cmd_name: qmp_capabilities, arguments: {}
The issue is a race condition in vcs_write(). When the console_lock is
temporarily dropped (to copy data from userspace), the vc_data pointer
obtained from vcs_vc() may become stale. After re-acquiring the lock,
vcs_vc() is called again to re-validate the pointer. If the vc has been
deallocated in the meantime, vcs_vc() returns NULL, and the while loop
breaks (with written > 0). However, after the loop, vcs_scr_updated(vc)
is still called with the now-NULL vc pointer, leading to a null pointer
dereference in the notifier chain (vcs_notifier dereferences param->vc).
Fix this by adding a NULL check for vc before calling vcs_scr_updated(). (CVE-2026-53385)
In the Linux kernel, the following vulnerability has been resolved:
fuse: re-lock request before replacing page cache folio
fuse_try_move_folio() unlocks the request on entry but does not
re-lock it on the success path. This means fuse_chan_abort() can end the
request and free the fuse_io_args (eg fuse_readpages_end()) while the
subsequent copy chain logic after fuse_try_move_folio() accesses the
fuse_io_args, leading to use-after-free issues.
Fix this by calling lock_request() before replace_page_cache_folio().
This ensures the request is locked on the success path which will
prevent the fuse_io_args from being freed while the later copying logic
runs, and also ensures that the ap->folios[i]->mapping is never null
since ap->folios[i] will always point to the newfolio after
replace_page_cache_folio(). (CVE-2026-53388)
In the Linux kernel, the following vulnerability has been resolved:
NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr (CVE-2026-53391)
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix posix_acl leak on SETACL decode failure (CVE-2026-53397)
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Fix SECINFO_NO_NAME decode error cleanup (CVE-2026-53398)
In the Linux kernel, the following vulnerability has been resolved:
fbdev: Fix fb_new_modelist to prevent null-ptr-deref in fb_videomode_to_var
info->var, a framebuffer's current mode, is expected to have a matching
entry in info->modelist. var_to_display() relies on this and treats a
failed fb_match_mode() as "This should not happen". fb_set_var() keeps it
true by adding the mode to the list on every change, and
do_register_framebuffer() does the same at registration.
store_modes() replaces the modelist from userspace. fb_new_modelist()
validates the new modes but does not check that info->var still has a
match. It relies on fbcon_new_modelist() to re-point consoles, but that
only handles consoles mapped to the framebuffer. With fbcon unbound there
are none, so info->var is left describing a mode that is no longer in the
list.
A later console takeover runs var_to_display(), where fb_match_mode()
returns NULL and leaves fb_display[i].mode NULL. fbcon_switch() passes it
to display_to_var(), and fb_videomode_to_var() dereferences the NULL mode.
Keep the current mode in the list in fb_new_modelist(), the same way
fb_set_var() does. (CVE-2026-53403)
In the Linux kernel, the following vulnerability has been resolved:
pNFS: Fix use-after-free in pnfs_update_layout() (CVE-2026-63800)
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done (CVE-2026-63801)
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level (CVE-2026-63807)
In the Linux kernel, the following vulnerability has been resolved:
exfat: fix potential use-after-free in exfat_find_dir_entry() (CVE-2026-63808)
In the Linux kernel, the following vulnerability has been resolved:
bpf: use kvfree() for replaced sysctl write buffer (CVE-2026-63809)
In the Linux kernel, the following vulnerability has been resolved:
keys: Pin request_key_auth payload in instantiate paths (CVE-2026-63823)
In the Linux kernel, the following vulnerability has been resolved:
KEYS: fix overflow in keyctl_pkey_params_get_2() (CVE-2026-63824)
In the Linux kernel, the following vulnerability has been resolved:
net: skmsg: preserve sg.copy across SG transforms (CVE-2026-63830)
Affected Packages:
kernel
Issue Correction:
Run dnf update kernel --releasever 2023.12.20260803 or dnf update --advisory ALAS2023-2026-2032 --releasever 2023.12.20260803 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
aarch64:
kernel-tools-debuginfo-6.1.177-224.371.amzn2023.aarch64
kernel-modules-extra-6.1.177-224.371.amzn2023.aarch64
perf-debuginfo-6.1.177-224.371.amzn2023.aarch64
kernel-tools-devel-6.1.177-224.371.amzn2023.aarch64
kernel-modules-extra-common-6.1.177-224.371.amzn2023.aarch64
perf-6.1.177-224.371.amzn2023.aarch64
bpftool-6.1.177-224.371.amzn2023.aarch64
kernel-tools-6.1.177-224.371.amzn2023.aarch64
bpftool-debuginfo-6.1.177-224.371.amzn2023.aarch64
python3-perf-6.1.177-224.371.amzn2023.aarch64
kernel-6.1.177-224.371.amzn2023.aarch64
python3-perf-debuginfo-6.1.177-224.371.amzn2023.aarch64
kernel-debuginfo-6.1.177-224.371.amzn2023.aarch64
kernel-headers-6.1.177-224.371.amzn2023.aarch64
kernel-livepatch-6.1.177-224.371-1.0-0.amzn2023.aarch64
kernel-debuginfo-common-aarch64-6.1.177-224.371.amzn2023.aarch64
kernel-devel-6.1.177-224.371.amzn2023.aarch64
src:
kernel-6.1.177-224.371.amzn2023.src
x86_64:
bpftool-debuginfo-6.1.177-224.371.amzn2023.x86_64
kernel-modules-extra-6.1.177-224.371.amzn2023.x86_64
kernel-tools-debuginfo-6.1.177-224.371.amzn2023.x86_64
kernel-tools-devel-6.1.177-224.371.amzn2023.x86_64
kernel-modules-extra-common-6.1.177-224.371.amzn2023.x86_64
perf-6.1.177-224.371.amzn2023.x86_64
python3-perf-debuginfo-6.1.177-224.371.amzn2023.x86_64
kernel-headers-6.1.177-224.371.amzn2023.x86_64
perf-debuginfo-6.1.177-224.371.amzn2023.x86_64
kernel-livepatch-6.1.177-224.371-1.0-0.amzn2023.x86_64
kernel-6.1.177-224.371.amzn2023.x86_64
kernel-tools-6.1.177-224.371.amzn2023.x86_64
bpftool-6.1.177-224.371.amzn2023.x86_64
python3-perf-6.1.177-224.371.amzn2023.x86_64
kernel-debuginfo-6.1.177-224.371.amzn2023.x86_64
kernel-debuginfo-common-x86_64-6.1.177-224.371.amzn2023.x86_64
kernel-devel-6.1.177-224.371.amzn2023.x86_64