SB2026081891 - Ubuntu update for linux
Published: August 18, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 7 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-53309)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to disclose sensitive information, modify data, or cause a denial of service.
The vulnerability exists due to an out-of-bounds read in dlm_match_regions() when comparing local and remote regions. A remote attacker can trigger the vulnerable region comparison to disclose sensitive information, modify data, or cause a denial of service.
2) Out-of-bounds read (CVE-ID: CVE-2026-53246)
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:L/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to disclose sensitive information or cause memory corruption.
The vulnerability exists due to an out-of-bounds read in sctp_unpack_cookie() and cached peer INIT chunk processing when processing a crafted COOKIE_ECHO chunk. A remote attacker can send a specially crafted COOKIE_ECHO chunk with an inflated cached INIT chunk length to disclose sensitive information or cause memory corruption.
The issue occurs in a listening SCTP server while walking parameters from the cached peer INIT chunk embedded after the cookie.
3) Out-of-bounds read (CVE-ID: CVE-2026-53224)
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 SCTP cookie processing in sctp_unpack_cookie(), sctp_process_init(), and sctp_raw_to_bind_addrs() when handling a malformed COOKIE_ECHO containing a truncated embedded INIT chunk or malformed address parameters. A remote attacker can send a specially crafted COOKIE_ECHO to cause a denial of service.
When cookie authentication is disabled, an oversized raw address list length can also be used to trigger the out-of-bounds read condition.
4) Out-of-bounds read (CVE-ID: CVE-2026-53043)
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 dlm_match_regions() when processing a crafted DLM_QUERY_REGION network message. A remote attacker can send a specially crafted network message to disclose sensitive information.
5) Double free (CVE-ID: CVE-2026-52993)
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 tipc_buf_append() when validating a reassembled skb after tipc_msg_validate() reallocates it. A local user can trigger the error-handling path with a crafted TIPC message to cause a denial of service.
6) 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.
7) Out-of-bounds read (CVE-ID: CVE-2026-43071)
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 dentry_hashtable when processing lookups with dhash_entries set to 1. A local user can trigger filesystem lookup operations to cause a denial of service.
The issue occurs because a single hash bucket can cause an invalid shift calculation that leads to access of unallocated memory.
Remediation
Install update from vendor's website.