SB2026081482 - Ubuntu update for linux-azure-6.17
Published: August 14, 2026
Breakdown by Severity
- Low
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- Critical
Description
This security bulletin contains information about 24 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-46113)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in KVM shadow paging when handling guest page table changes between VM entries. A local user can modify guest page tables to create a stale reverse-mapping entry and trigger a stale rmap walk to cause a denial of service.
This can be triggered during operations such as dirty logging or MMU notifier invalidations.
2) Out-of-bounds read (CVE-ID: CVE-2026-31405)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to an out-of-bounds read in handle_one_ule_extension() extension handler tables when processing network-controlled ULE extension header data. A remote attacker can send a specially crafted SNDU with an extension header type value of 255 to execute arbitrary code.
The out-of-bounds value may be dereferenced and called as a function pointer.
3) Use-after-free (CVE-ID: CVE-2026-31414)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in nf_conntrack_expect when dumping the helper name via ctnetlink or /proc. A local user can trigger access to freed conntrack helper state to cause a denial of service.
The issue involves unsafe use of nfct_help() without holding a reference to the master conntrack.
4) Use-after-free (CVE-ID: CVE-2026-31501)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in the RX path timestamp handling in the icssg-prueth driver when processing received packets through the timestamp path. A local user can trigger packet processing that reaches the timestamp path to cause a denial of service.
5) Use-after-free (CVE-ID: CVE-2026-31589)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in folio_unmap_invalidate() when accessing mapping->a_ops after the folio has been removed from the mapping and the mapping can be removed. A local user can trigger the vulnerable code path to cause a denial of service.
6) Integer overflow (CVE-ID: CVE-2026-31633)
CWE-ID: CWE-190 - Integer overflow
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to integer overflow in rxgk_verify_response() when processing a response packet. A remote attacker can send a specially crafted response packet to cause a denial of service.
7) Out-of-bounds read (CVE-ID: CVE-2026-31636)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in rxgk_verify_authenticator() when parsing malformed RESPONSE authenticators. A remote attacker can send a specially crafted RESPONSE authenticator to cause a denial of service.
8) Out-of-bounds write (CVE-ID: CVE-2026-31705)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in smb2_get_ea() when processing crafted QUERY_INFO compound requests. A remote user can send a specially crafted request to cause a denial of service.
The issue occurs when EA alignment padding is applied after an EA value exactly fills the remaining response buffer, causing 1 to 3 bytes to be written past the boundary into adjacent kernel heap memory.
9) Race condition (CVE-ID: CVE-2026-43198)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a race condition in tcp_v6_syn_recv_sock() when handling IPv6 TCP connection requests. A remote attacker can send network traffic that triggers the race to cause a denial of service.
The issue occurs because a child socket may become visible in the TCP ehash table before its IPv6 state is fully initialized.
10) Use-after-free (CVE-ID: CVE-2026-43379)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in smb_lazy_parent_lease_break_close() when handling concurrent lease break close operations. A local user can trigger a race condition to cause a denial of service.
11) Improper update of reference count (CVE-ID: CVE-2026-43465)
CWE-ID: CWE-911 - Improper Update of Reference Count
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper reference counting in the mlx5 XDP receive path when processing XDP multi-buffer packets on striding RQ. A local user can trigger XDP actions that alter the XDP buffer layout to cause a kernel warning and crash.
The issue affects multiple XDP actions, including XDP_TX, XDP_REDIRECT, XDP_PASS, and packet drops after buffer layout changes caused by bpf_xdp_pull_data() or bpf_xdp_adjust_tail().
12) Use-after-free (CVE-ID: CVE-2026-43499)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in remove_waiter() when rolling back a proxy lock from futex_requeue(). A local user can trigger the affected rtmutex slowlock and proxy-lock rollback path to cause a denial of service.
The issue can leave waiter task state uncleared and operate on the wrong top priority waiter task.
13) Use-after-free (CVE-ID: CVE-2026-53359)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in the KVM x86 shadow paging logic when changing a PDE mapping from outside the guest and deleting a memslot. A local user can trigger stale rmap entries and subsequent dereference of a freed sptep to cause a denial of service.
The issue occurs when a modified PDE points to a non-leaf page, causing a role mismatch between reused shadow pages for large 2MB mappings and new 4KB mappings.
14) Race condition (CVE-ID: CVE-2026-46137)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition in mptcp_pm_add_timer() when handling ADD_ADDR retransmission timer callbacks. A local user can trigger concurrent access to cause a denial of service.
15) Use-after-free (CVE-ID: CVE-2026-46242)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause memory corruption.
The vulnerability exists due to a use-after-free in ep_remove() in fs/eventpoll.c when removing epoll file references during a race with file release handling. A local user can trigger a race condition to cause memory corruption.
The issue involves the epoll-watches-epoll case and a concurrent __fput() path that can lead to operations on freed structures.
16) Out-of-bounds write (CVE-ID: CVE-2026-46331)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause memory corruption.
The vulnerability exists due to an out-of-bounds write in tcf_pedit_act() when processing packet edit actions with typed keys and runtime header offsets. A local user can supply crafted pedit parameters that cause writes to a region that has not been properly copy-on-written to cause memory corruption.
The issue can involve negative offsets such as Ethernet header edits at ingress.
17) Use-after-free (CVE-ID: CVE-2026-52924)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in the SCTP outqueue and stream scheduler state handling when processing a stale COOKIE-ECHO condition. A remote attacker can send a stale cookie error during SCTP association handling to cause a denial of service.
The issue occurs when an association is rolled back from COOKIE_ECHOED to COOKIE_WAIT, leaving scheduler state referencing freed stream entries.
18) Out-of-bounds read (CVE-ID: CVE-2026-52989)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds condition in nvmet_tcp_build_pdu_iovec() and the NVMe target TCP receive path when processing crafted PDU length or offset values. A remote attacker can send a specially crafted network PDU to cause a denial of service.
The issue occurs because a fatal error is not propagated to callers, leaving cmd->recv_msg.msg_iter uninitialized before subsequent receive handling uses it.
19) Race condition (CVE-ID: CVE-2026-53086)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition in the bcmgenet_timeout handler when handling a transmit queue timeout. A local user can trigger a transmit queue timeout to cause a denial of service.
20) Improper input validation (CVE-ID: CVE-2026-53131)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper input validation in netfilter Ethernet header handling when processing packets that reach ip6t_eui64, xt_mac, ipset bitmap:ip,mac, hash:ip,mac, hash:mac, or nf_log_syslog code paths without a valid Ethernet MAC header. A remote attacker can send a specially crafted packet to cause a denial of service.
The issue occurs because these paths access eth_hdr(skb) after insufficient validation that the skb is associated with an Ethernet device and that a full MAC header is present.
21) Out-of-bounds write (CVE-ID: CVE-2026-53176)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in isert_login_recv_done() and isert_rx_login_req() in drivers/infiniband/ulp/isert/ib_isert.c when processing a login PDU shorter than ISER_HEADERS_LEN. A remote attacker can send a specially crafted login send work request to cause a denial of service.
The vulnerable code path is reachable during the login phase before iSCSI authentication.
22) Use-after-free (CVE-ID: CVE-2026-53212)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in nft_tunnel_obj_destroy() in net/netfilter/nft_tunnel.c when processing packets that still hold a reference to metadata_dst after object destruction. A local user can trigger packet queuing and object destruction to cause a denial of service.
Exploitation requires packets to remain queued, such as in a netem qdisc, until they are later dequeued.
23) Out-of-bounds read (CVE-ID: CVE-2026-53225)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in __sctp_rcv_asconf_lookup() in net/sctp/input.c when processing a truncated trailing ASCONF chunk containing a declared IPv6 address parameter. A remote attacker can send a specially crafted SCTP packet to disclose sensitive information.
The issue is reachable from the no-association lookup path.
24) Use-after-free (CVE-ID: CVE-2026-53228)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to a use-after-free in the ipip6_tunnel_xmit() function in the SIT IPv6 tunneling implementation when handling GSO packets after offload processing. A local user can trigger transmission of a crafted packet to disclose sensitive information.
The issue occurs because a cached inner IPv6 header pointer may become stale if the skb head is moved during offload handling, and the stale pointer may later be used to read header fields.
Remediation
Install update from vendor's website.