SB2026110433 - SUSE update for the Linux Kernel (Live Patch 87 for SUSE Linux Enterprise 12 SP5)
Published: November 4, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 vulnerabilities.
1) Out-of-bounds write (CVE-ID: CVE-2026-74469)
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 SCTP sock_diag when processing a diagnostic dump after adding many unique peer transports. A local user can add unique peer addresses until the 16-bit transport_count wraps and trigger a diagnostic dump to cause a denial of service.
The issue occurs when the association accumulates 65,536 unique peer transports, causing transport_count to wrap to zero while peer addresses are still copied from transport_addr_list.
2) NULL pointer dereference (CVE-ID: CVE-2026-89544)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 improper error handling in the SUNRPC gssx XDR option-array decoder when handling an allocation failure while decoding an option array. A local user can trigger the decoder's error path to cause a denial of service.
The affected error paths also include a group_info reference-count leak and a latent use-after-free condition.
3) Integer underflow (CVE-ID: CVE-2026-89551)
CWE-ID: CWE-191 - Integer underflow
CVSSv4: 0 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause downstream XDR decoders to use an incorrect stream bound.
The vulnerability exists due to an integer underflow in xdr_buf_trim() when processing GSS Kerberos v2 data whose recorded buffer length is smaller than the associated I/O vector lengths. A remote attacker can cause xdr_buf_trim() to consume more bytes than buf->len records to cause downstream XDR decoders to use an incorrect stream bound.
4) Out-of-bounds write (CVE-ID: CVE-2026-89674)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to write beyond the reserved XDR buffer or disclose uninitialized kernel memory.
The vulnerability exists due to an incorrect XDR buffer size calculation in nfsd4_ff_encode_layoutget() when encoding layoutget responses with short user or group strings and an odd-sized file handle. A remote attacker can request a layoutget operation to write beyond the reserved XDR buffer or disclose uninitialized kernel memory.
5) Use-after-free (CVE-ID: CVE-2026-98432)
CWE-ID: CWE-416 - Use After Free
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 potentially cause a denial of service through access to freed IPv6 request socket options.
The vulnerability exists due to use-after-free in tcp_v6_reqsk_destructor() when request socket migration leaves concurrent processing using shared options after they have been freed. A remote attacker can send TCP traffic that encounters concurrent request socket migration and destruction to potentially cause a kernel crash.
The affected ipv6_opt options are only set by CALIPSO.
6) Use-after-free (CVE-ID: CVE-2026-98432)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to use-after-free in the Linux kernel IPv4 TCP socket option handling when socket destruction frees shared options while another CPU is still using them to build a SYNACK or create a child socket. A remote attacker can send TCP traffic that encounters these concurrent processing paths to potentially cause a kernel crash.
The request socket migration path requires net.ipv4.tcp_migrate_req=1 or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE program. IPv6 is not affected by the child socket ownership-transfer path because it duplicates the options.
Remediation
Install update from vendor's website.