SB2026080780 - Debian update for linux
Published: August 7, 2026
Breakdown by Severity
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Description
This security bulletin contains information about 29 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-64567)
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 io_ctl_check_crc() in the btrfs free space cache loader when loading a corrupted v1 free space cache. A local user can modify free space cache header counts to exceed the number of allocated pages to cause a denial of service.
The invalid out-of-bounds slot is treated as a struct page and can lead to a general protection fault during crc32c() processing.
2) Use-after-free (CVE-ID: CVE-2026-64584)
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 f_midi driver work handler when handling concurrent userspace writes to an open rawmidi substream during device teardown. A local user can write to a rawmidi substream to trigger pending work on a freed midi object and cause a denial of service.
The issue occurs because the rawmidi device can remain usable by an open substream after USB endpoints have been disabled and before the final midi object reference is released.
3) Use-after-free (CVE-ID: CVE-2026-64583)
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 Broadcom BDC USB gadget UDC driver IRQ handler and delayed work processing when tearing down the driver during device removal. A local user can trigger a shared interrupt or delayed work execution during teardown to cause a denial of service.
The issue occurs in the window after teardown of endpoint and DMA-related structures begins while the IRQ handler remains deliverable, and delayed work may also execute after removal.
4) Double free (CVE-ID: CVE-2026-64580)
CWE-ID: CWE-415 - Double 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 double free in xfrm6_fill_dst() when handling an error path after in6_dev_get(dev) returns NULL. A local user can trigger network operations that reach the affected code path to cause a denial of service.
The issue underflows a net_device reference count and can lead to kernel warnings while waiting for the device to become free.
5) Improper control of a resource through its lifetime (CVE-ID: CVE-2026-64579)
CWE-ID: CWE-664 - Improper control of a resource through its lifetime
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 state management in xfrm_hash_rebuild() in the xfrm policy subsystem when rebuilding policy hashes under memory pressure. A local user can trigger policy reinsertions that take the allocating inexact insertion path and cause a kernel crash.
The issue is reachable under memory pressure and can be triggered deterministically with failslab.
6) Out-of-bounds read (CVE-ID: CVE-2026-64578)
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 ksmbd_smb2_check_message() when processing a crafted compound SMB2 request. A remote attacker can send a specially crafted compound request with a trailing element that is too small to hold StructureSize2 to disclose sensitive information.
The issue occurs when the last compound element contains only a 64-byte SMB2 header, causing a 2-byte read at offset 64 to extend past the receive buffer.
7) Unchecked Return Value (CVE-ID: CVE-2026-64577)
CWE-ID: CWE-252 - Unchecked Return Value
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 handling of a failed buffer pull in gtp1u_send_echo_resp() in the Linux kernel GTP implementation when processing a crafted short echo request packet. A remote attacker can send a specially crafted packet to cause a kernel panic.
The issue is triggered by a 16 to 19 byte echo request that causes skb_pull_data() to fail while execution continues and skb data is moved below the buffer head.
8) Use of Uninitialized Variable (CVE-ID: CVE-2026-64576)
CWE-ID: CWE-457 - Use of Uninitialized Variable
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 of uninitialized memory in nh_res_bucket_migrate() when handling rtnetlink nexthop operations. A local user can send a specially crafted netlink message to cause a denial of service.
The issue can lead to a general protection fault and kernel panic when an error path dereferences an uninitialized extack message pointer.
9) Use-after-free (CVE-ID: CVE-2026-64574)
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 ieee80211_if_read_link and related mac80211 link handling when reading debugfs link files after a vif link update error path leaves stale debugfs entries for newly added links. A local user can open and read a debugfs link file referencing freed memory to cause a denial of service.
The issue is triggered when drv_change_vif_links() fails after new links have been allocated and initialized.
10) Integer underflow (CVE-ID: CVE-2026-64573)
CWE-ID: CWE-191 - Integer underflow
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 and out-of-bounds write in the qca_tlv_check_data() TLV parser when parsing a crafted firmware TLV with an undersized NVM tag length. A local user can supply a specially crafted firmware image to trigger out-of-bounds access and cause a denial of service.
The issue is caused by an integer underflow in the loop bound calculation for TLV_TYPE_NVM records.
11) Use-after-free (CVE-ID: CVE-2026-64572)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local privileged user to cause a denial of service.
The vulnerability exists due to a use-after-free in fib_table_lookup() and the IPv4 FIB alias list handling in fib_trie.c when processing concurrent route insertion failure and lookup operations. A local privileged user can trigger a route insertion error path and perform a concurrent lookup to cause a denial of service.
Exploitation requires CAP_NET_ADMIN and a registered FIB notifier that can reject a route, such as when an IPv4 FIB resource is exhausted on a netdevsim device.
12) Out-of-bounds read (CVE-ID: CVE-2026-64571)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 2.4 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows an attacker with physical access to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in p54_rx_eeprom_readback() when processing a device-supplied EEPROM readback frame. An attacker with physical access can send a truncated frame with a matching advertised length to disclose sensitive information.
The issue can be triggered by a malicious USB device.
13) Double free (CVE-ID: CVE-2026-64570)
CWE-ID: CWE-415 - Double 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 double free in ieee80211_set_fils_discovery() when handling FILS discovery template updates after an allocation failure. A local user can trigger an allocation failure and cause the same object to be queued for freeing multiple times to cause a denial of service.
The issue is triggered when a later update or AP teardown re-queues an object that still points to memory already scheduled for RCU freeing.
14) NULL pointer dereference (CVE-ID: CVE-2026-64569)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 null pointer dereference in mpls_valid_fib_dump_req() when handling an RTM_GETROUTE dump request for AF_MPLS with strict checking and no RTA_OIF attribute. A local user can send a specially crafted netlink request to cause a denial of service.
The issue affects CONFIG_INET=n builds.
15) Double free (CVE-ID: CVE-2026-64568)
CWE-ID: CWE-415 - Double 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 double free in ieee80211_set_unsol_bcast_probe_resp() when handling updates to unsolicited broadcast probe response templates after an allocation failure. A local user can trigger a later update or AP teardown to cause a denial of service.
The issue occurs because the pointer can still reference an object already queued for RCU freeing after kzalloc() fails.
16) NULL pointer dereference (CVE-ID: CVE-2025-40098)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 perform a denial of service (DoS) attack.
The vulnerability exists due to NULL pointer dereference within the cs35l41_get_acpi_mute_state() function in sound/hda/codecs/side-codecs/cs35l41_hda.c. A local user can perform a denial of service (DoS) attack.
17) Heap-based buffer overflow (CVE-ID: CVE-2026-64565)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 7 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows an attacker with physical access to execute arbitrary code.
The vulnerability exists due to a heap-based buffer overflow in ims_pcu_handle_response() when processing oversized packets from a malicious USB device. An attacker with physical access can send a specially crafted oversized USB packet to execute arbitrary code.
The issue arises because ims_pcu_process_data() does not properly bound-check read_pos, allowing it to be overwritten and later used as a controlled index during response handling.
18) Use-after-free (CVE-ID: CVE-2026-64564)
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 a use-after-free in sctp_process_asconf_param() when processing crafted SCTP ASCONF DEL-IP parameters. A remote attacker can send a specially crafted SCTP ASCONF message to cause a denial of service.
The issue can occur when a single ASCONF carries DEL-IP parameters that free the cached transport and a later wildcard DEL-IP reuses the dangling transport pointer.
19) Use-after-free (CVE-ID: CVE-2026-64563)
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 rhashtable_walk_next in the rhashtable iterator logic when resuming multi-fragment rhashtable walks across walk_stop and walk_start boundaries after a table restart. A local user can trigger a stale iterator pointer dereference to cause a denial of service.
Concrete affected call paths include netlink_diag and TIPC.
20) Use-after-free (CVE-ID: CVE-2026-64562)
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 nested VMX shadow VMCS handling when freeing nested virtualization state asynchronously with respect to loaded VMCS clearing during vCPU migration. A local user can trigger nested virtualization cleanup and vCPU migration to execute VMCLEAR on a freed shadow VMCS and cause a denial of service.
The issue occurs because vmcs01 may still reference the shadow VMCS until explicit VMCLEAR completes.
21) Improper Initialization (CVE-ID: CVE-2026-64561)
CWE-ID: CWE-665 - Improper Initialization
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 state management in the KVM x86 shadow MMU page fault handling code when processing stale page faults after reclaiming shadow pages. A local user can trigger page faults that lead KVM to map memory into an invalid root to cause a denial of service.
The issue occurs when reclaiming shadow pages invalidates an in-use root, causing child shadow pages created during map or fetch operations to inherit an invalid role and violate the invariant that invalid shadow pages must not appear on the list of active MMU pages.
22) Improper handling of exceptional conditions (CVE-ID: CVE-2026-64290)
CWE-ID: CWE-755 - Improper Handling of Exceptional Conditions
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 exception handling in iommufd_fault_fops_read() when handling a copy_to_user() failure while reading fault events. A local user can trigger a failing read operation to cause a denial of service.
The issue can lead to an infinite retry loop that spins the reader at 100% CPU while holding fault->mutex.
23) Improper input validation (CVE-ID: CVE-2026-64280)
CWE-ID: CWE-20 - Improper input validation
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 input validation in afu_ioctl_dma_map() when handling a DFL_FPGA_PORT_DMA_MAP ioctl request with a user-supplied length. A local user can provide an excessively large length value to cause a denial of service.
24) Improper control of a resource through its lifetime (CVE-ID: CVE-2026-64205)
CWE-ID: CWE-664 - Improper control of a resource through its lifetime
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 resource management in i801_access() in the i2c-i801 driver when handling an error path after a failed pre-check. A local user can trigger concurrent access to the SMBus controller to cause a denial of service.
The issue occurs when the driver clears SMBus hardware status and ownership state without actually owning the controller, which can corrupt the SMBus hardware state machine and lead to a console livelock and hung task panic.
25) Improper access control (CVE-ID: CVE-2026-53090)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to bypass BPF verifier checks.
The vulnerability exists due to improper access control in the Linux kernel BPF verifier when analyzing ld_{abs,ind} instructions in subprograms. A local user can load a crafted BPF program to bypass BPF verifier checks.
The issue affects subprograms where ld_{abs,ind} instructions are permitted, including cases involving BTF-annotated subprograms with scalar return types.
26) Out-of-bounds read (CVE-ID: CVE-2026-53078)
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:H/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 an out-of-bounds read in BPF sock_ops context field access handling when accessing ctx fields with the same destination and source register. A local user can trigger the flawed register handling to disclose sensitive information.
The issue occurs when the fullsock or locked_tcp_sock check is false, causing a stale ctx pointer to be retained.
27) Out-of-bounds read (CVE-ID: CVE-2026-53078)
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 BPF sock_ops context field access handling when accessing ctx fields with the same destination and source register. A local user can trigger the flawed register handling to cause a denial of service.
The issue occurs when the fullsock or locked_tcp_sock check is false, causing a stale ctx pointer to be retained and used as a bogus socket pointer.
28) Improper locking (CVE-ID: CVE-2026-45901)
CWE-ID: CWE-667 - Improper Locking
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 locking in nf_tables reset path when nft reset, ipset list, and iptables-nft with '-m set' rule run concurrently. A local user can trigger concurrent operations to cause a denial of service.
The issue results from a circular lock dependency involving commit_mutex, nfnl_subsys_ipset, and nlk_cb_mutex.
29) Race condition (CVE-ID: CVE-2026-45897)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause incorrect counter values to be reported.
The vulnerability exists due to a race condition in nft_counter when performing concurrent dump-and-reset operations. A local user can trigger parallel counter resets to cause incorrect counter values to be reported.
Remediation
Install update from vendor's website.