SB2026081493 - Ubuntu update for linux-lowlatency
Published: August 14, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 17 vulnerabilities.
1) 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.
2) Out-of-bounds read (CVE-ID: CVE-2026-43083)
CWE-ID: CWE-125 - Out-of-bounds read
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 an out-of-bounds read in __ioam6_fill_trace_data() when processing packets with trace->type.bit6 set on the RX path. A local user can trigger the kernel to access an invalid transmit queue index to cause a denial of service.
The issue occurs when the ingress device has more RX queues than the egress device has TX queues.
3) Out-of-bounds read (CVE-ID: CVE-2026-43197)
CWE-ID: CWE-125 - Out-of-bounds read
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 an out-of-bounds read in netconsole_write when processing console messages that are not nul-terminated. A local user can trigger processing of a specially crafted message to cause a denial of service.
4) 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.
5) 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().
6) 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.
7) Incorrect calculation (CVE-ID: CVE-2026-46325)
CWE-ID: CWE-682 - Incorrect Calculation
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 memory address conversion in the RDMA RXE memory region handling code when processing memory regions with page sizes different from the system PAGE_SIZE. A local user can register or access a crafted memory region layout to cause a denial of service.
The issue can lead to incorrect iova-to-va translation and a kernel panic.
8) 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.
9) Integer overflow (CVE-ID: CVE-2026-52914)
CWE-ID: CWE-190 - Integer overflow
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 an integer overflow in the batman-adv fragment reassembly logic when processing malformed fragment chains. A local user can send malformed fragments to cause a denial of service.
10) 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.
11) Use of Uninitialized Variable (CVE-ID: CVE-2026-52931)
CWE-ID: CWE-457 - Use of Uninitialized Variable
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause undefined behavior.
The vulnerability exists due to use of uninitialized memory in batadv_tp_recv_ack() and batadv_tp_stop() in the tp_meter component when processing a malicious ACK packet for a tp_meter session while the node is acting as a receiver. A remote attacker can send a malicious ACK packet to cause undefined behavior.
The issue occurs when sender-only members are accessed for tp_vars in the BATADV_TP_RECEIVER role during an ongoing tp_meter session.
12) Out-of-bounds read (CVE-ID: CVE-2026-53151)
CWE-ID: CWE-125 - Out-of-bounds read
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 an out-of-bounds read in rxrpc_input_soft_acks() when parsing the SACK table from a fragmented UDP packet. A remote attacker can send a deliberately fragmented packet to cause a denial of service.
The issue affects AF_RXRPC extended ACK parsing, and exploitation likely requires a deliberately pre-generated fragmented packet.
13) 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.
14) 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.
15) Use-after-free (CVE-ID: CVE-2026-53215)
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 attacker to cause a denial of service.
The vulnerability exists due to a use-after-free in the mvpp2 RX buffer handling in drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c when processing received packets through XDP or skb paths. A local attacker can trigger packet processing that returns a retired buffer to the BM pool to cause a denial of service.
Hardware may DMA into memory that is no longer owned by the RX ring after the buffer has been recycled, redirected, queued for XDP_TX, or freed.
16) 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.
17) 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.