SB2026090918 - Red Hat Enterprise Linux 8 update for kernel
Published: September 9, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 11 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2021-47600)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error within the rebalance_children() function in drivers/md/persistent-data/dm-btree-remove.c. A local user can escalate privileges on the system.
2) Memory leak (CVE-ID: CVE-2023-52924)
CWE-ID: CWE-401 - Missing release of memory after effective lifetime
CVSSv4: 5.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:U/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 memory leak within the nft_rbtree_walk() function in net/netfilter/nft_set_rbtree.c, within the nft_rhash_walk() function in net/netfilter/nft_set_hash.c, within the nf_tables_dump_setelem() function in net/netfilter/nf_tables_api.c. A local user can perform a denial of service (DoS) attack.
3) Improper input validation (CVE-ID: CVE-2026-31411)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/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 sigd_send() when handling sendmsg() input containing a forged vcc pointer. A local user can send a specially crafted message to cause a denial of service.
Exploitation requires control of the ATM signaling daemon role via the ATMSIGD_CTRL ioctl.
4) Use-after-free (CVE-ID: CVE-2026-46120)
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 ip6erspan_changelink() when changing link configuration after network namespace migration. A local user can trigger tunnel reinsertion into the wrong per-netns hash to cause a denial of service.
The issue is reachable from an unprivileged user namespace.
5) Out-of-bounds write (CVE-ID: CVE-2026-53016)
CWE-ID: CWE-787 - Out-of-bounds write
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 write in ccp_aes_complete() when processing AF_ALG rfc3686-ctr-aes-ccp requests. A local user can supply a request with an 8-byte IV to cause a denial of service.
6) Use-after-free (CVE-ID: CVE-2026-53006)
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 icmpv6_rcv() in the IPv6 ICMP handling code when processing ICMPv6 packets. A remote attacker can send a specially crafted ICMPv6 packet to cause a denial of service.
7) Race condition (CVE-ID: CVE-2026-53071)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 6.1 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to corrupt kernel memory.
The vulnerability exists due to a race condition in l2cap_ecred_reconf_rsp in the L2CAP subsystem when processing a crafted L2CAP ECRED reconfiguration response from a remote BLE device. A remote attacker can send a specially crafted L2CAP ECRED reconfiguration response to corrupt kernel memory.
Exploitation requires concurrent channel list iteration by another thread.
8) Heap-based buffer overflow (CVE-ID: CVE-2026-53196)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 5.1 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows an attacker with physical access to cause a denial of service or execute arbitrary code.
The vulnerability exists due to a heap-based buffer overflow in get_manuf_info() in the io_ti USB serial driver when processing a crafted USB device EEPROM descriptor. An attacker with physical access can connect a malicious USB device with a forged Size field to trigger the overflow and cause a denial of service or execute arbitrary code.
The out-of-bounds access is compounded because a checksum routine also iterates over the device-controlled length after the EEPROM data is read.
9) Out-of-bounds read (CVE-ID: CVE-2026-64191)
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 out-of-bounds read and out-of-bounds write in stub_xfer() in the i2c-stub driver when handling an I2C_SMBUS ioctl with I2C_SMBUS_I2C_BLOCK_DATA and an invalid block length. A local user can issue a crafted ioctl request with data->block[0] greater than 32 to cause a denial of service.
The issue affects the development and test i2c-stub driver, which is not built by default and must be loaded with a chip_addr= parameter.
10) Out-of-bounds write (CVE-ID: CVE-2026-64268)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 7.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to write out of bounds.
The vulnerability exists due to an out-of-bounds write in siw_proc_rresp() in drivers/infiniband/sw/siw/siw_qp_rx.c when processing Read Response DDP segments for an outstanding RREAD over an established RDMA connection. A remote user can send Read Response segments with more total payload than requested while keeping the DDP Last flag clear to write out of bounds.
Exploitation requires a connected siw peer on an established RDMA connection over routable TCP.
11) Expired pointer dereference (CVE-ID: CVE-2026-17523)
CWE-ID: CWE-825 - Expired pointer dereference
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to execute arbitrary code within the kernel and escalate privileges.
The vulnerability exists due to CWE-825 in net/can/bcm.c in can: bcm when processing local CAN BCM operations. A local user can exploit the flaw to execute arbitrary code within the kernel and escalate privileges.
Successful exploitation can allow the attacker to gain root privileges and take full control of the affected system.
Remediation
Install update from vendor's website.