SB2026082605 - Red Hat Enterprise Linux 9 update for kernel
Published: August 26, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 13 vulnerabilities.
1) Improper locking (CVE-ID: CVE-2025-68211)
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 perform a denial of service (DoS) attack.
The vulnerability exists due to improper locking within the should_skip_rmap_item() and scan_get_next_rmap_item() functions in mm/ksm.c. A local user can perform a denial of service (DoS) attack.
2) Use of uninitialized resource (CVE-ID: CVE-2026-23003)
CWE-ID: CWE-908 - Use of Uninitialized Resource
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 use of uninitialized resource within the __ip6_tnl_rcv() function in net/ipv6/ip6_tunnel.c. A local user can perform a denial of service (DoS) attack.
3) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-43114)
CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation
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 handling of stale bits in nft_set_pipapo_avx2 match functions in the netfilter pipapo set implementation when processing crafted set elements during avx2-based matching. A local user can load and reload a crafted pipapo set to cause a denial of service.
The issue occurs with avx2 matching functions and can cause a non-matching expired entry to be treated as a match after a set flush and reload operation.
4) 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.
5) Improper access control (CVE-ID: CVE-2026-52920)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to bypass inbound IPsec policy matching restrictions.
The vulnerability exists due to improper access control in the xt_policy netfilter matcher when processing strict mode inbound policy matching. A remote attacker can send network traffic that traverses a multi-element inbound rule to bypass inbound IPsec policy matching restrictions.
The issue affects strict matching of multi-element inbound rules.
6) Use-after-free (CVE-ID: CVE-2026-53185)
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 zram_bvec_write_partial() when processing partial writes for ZRAM_WB slots. A local user can trigger an asynchronous backing device read and subsequent access to a freed page to cause a denial of service.
The issue occurs because the read operation may still be in flight when the buffer page is freed.
7) 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.
8) Out-of-bounds read (CVE-ID: CVE-2026-53268)
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 out-of-bounds read in the conntrack_irc helper when parsing IRC DCC commands. A remote attacker can send specially crafted IRC traffic to cause a denial of service.
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) Use-after-free (CVE-ID: CVE-2026-64189)
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 ip_set_dump_do() and ip_set_dump_done() in the ipset netfilter subsystem when handling netlink dump operations concurrently with ip_set_list resizing. A local user can trigger concurrent netlink dump and set creation operations to cause a denial of service.
The issue can lead to a general protection fault and kernel panic.
11) Out-of-bounds read (CVE-ID: CVE-2026-64277)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information and overwrite adjacent kernel memory.
The vulnerability exists due to an out-of-bounds read and out-of-bounds write in the synaptics-rmi4 F3A GPIO keymap handling in drivers/input/rmi4/rmi_f3a.c when processing a device that reports a gpio_count greater than the allocated keymap size. A local user can open the evdev node and invoke keymap ioctls to disclose sensitive information and overwrite adjacent kernel memory.
The information disclosure occurs through EVIOCGKEYCODE leaking adjacent slab memory to user space, while EVIOCSKEYCODE writes a caller-controlled value past the buffer.
12) Out-of-bounds read (CVE-ID: CVE-2026-64276)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service or disclose sensitive information.
The vulnerability exists due to out-of-bounds read and out-of-bounds write in the rmi_f30_attention handler and EVIOCGKEYCODE/EVIOCSKEYCODE ioctl handling in the synaptics-rmi4 F30 driver when processing a device that reports a gpioled_count greater than 6 with GPIO support enabled. A local user can trigger the attention interrupt or use EVIOCGKEYCODE/EVIOCSKEYCODE ioctls to cause a denial of service or disclose sensitive information.
The issue occurs because the keymap allocation is smaller than the gpioled_count value used for iteration and keycode bounds.
13) Use-after-free (CVE-ID: CVE-2026-74581)
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 fib6_rule_lookup() and fib6_rule_suppress() in the IPv6 routing rules handler when processing suppressed IPv6 route lookups. A local user can trigger route lookups involving a suppressing rule to cause a denial of service.
The issue occurs because a stale dst entry can be returned after the released route remains referenced in the lookup result.
Remediation
Install update from vendor's website.