Ubuntu Security Advisories

It was discovered that cpio incorrectly sanitized hard-link targets when extracting tar archives in copy-in mode. If a user or automated system were tricked into extracting a specially crafted tar archive, an attacker could possibly use this issue to create hard links to files outside the extraction directory, even when using the --no-absolute-filenames option. (CVE-2026-66484) It was discovered that cpio did not properly bound the stack memory allocated for pathnames during archive extraction. If a user or automated system were tricked into extracting a specially crafted cpio archive, an attacker could possibly use this issue to cause cpio to crash, resulting in a denial of service. (CVE-2026-66485) It was discovered that cpio did not properly escape archive member names when listing archive contents. If a user or automated system were tricked into listing a specially crafted archive, an attacker could possibly use this issue to inject misleading output or malicious terminal control sequences. (CVE-2026-66486)

It was discovered that OpenZFS incorrectly handled authorization checks for certain ioctl operations on Linux. A local attacker could possibly use this issue to perform pool-administrative operations or access privileged information, resulting in an authorization bypass.

Several security issues were discovered in the WebKitGTK Web and JavaScript engines. If a user were tricked into viewing a malicious website, a remote attacker could exploit a variety of issues related to web browser security, including cross-site scripting attacks, denial of service attacks, and arbitrary code execution.

It was discovered that libblkid in util-linux had a heap use-after-free vulnerability during nested partition probing. An attacker who could present a crafted block device image could possibly use this issue to obtain sensitive information or cause a denial of service. (CVE-2026-13595) It was discovered that the mount utility in util-linux had a time-of-check- time-of-use vulnerability when setting up loop devices. A local attacker could possibly use this issue to obtain unauthorized read access to root- protected files and block devices. (CVE-2026-27456) It was discovered that the login utility in util-linux improperly canonicalized hostnames when invoked with the -h option. A remote attacker could possibly use this issue to bypass host-based access control rules. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-3184) It was discovered that libmount in util-linux had a time-of-check-time-of- use vulnerability in its ownership hook. A local attacker could possibly use this issue to gain elevated privileges. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-53612) It was discovered that libmount in util-linux had a time-of-check-time-of- use vulnerability that allowed target path redirection during mount operations. A local attacker could possibly use this issue to gain elevated privileges. (CVE-2026-53613) It was discovered that libmount in util-linux improperly handled the LIBMOUNT_FORCE_MOUNT2 environment variable in the SUID mount utility. A local attacker could possibly use this issue to bypass nosuid and noexec mount options and gain elevated privileges. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-53614) It was discovered that libblkid in util-linux had an integer overflow vulnerability when parsing DOS partition tables. An attacker who could present a crafted block device image could possibly use this issue to cause a denial of service. (CVE-2026-53615)

It was discovered that UDisks did not correctly validate the caller identity when handling the as-user option in the org.freedesktop.UDisks2.Filesystem.Mount() D-Bus method. A local attacker with an active console session could possibly use this issue to mount filesystems on behalf of arbitrary users, including privileged accounts, leading to local privilege escalation.

USN-8673-1 fixed vulnerabilities in OpenSSL. The update inadvertently left out the fix for CVE-2026-75803 in Ubuntu 26.04 LTS. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that OpenSSL incorrectly handled the QUIC server incoming channel queue. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-14456) It was discovered that OpenSSL incorrectly handled signature algorithm selection when using Raw Public Keys. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-14457) It was discovered that OpenSSL incorrectly handled QUIC INITIAL packet processing. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-18798) It was discovered that OpenSSL incorrectly handled buffering of DTLS records for a future epoch. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. (CVE-2026-54874) It was discovered that OpenSSL incorrectly handled CMS key unwrapping. A remote attacker could possibly use this issue to cause a heap buffer overflow, leading to a denial of service or arbitrary code execution. (CVE-2026-63072) It was discovered that OpenSSL incorrectly validated the sender distinguished name in CMP response messages. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-63073) It was discovered that OpenSSL incorrectly limited the growth of an internal certificate cache used during CMP operations. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. (CVE-2026-63074) It was discovered that OpenSSL incorrectly handled QUIC ACK-only packet retention. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-63075) It was discovered that OpenSSL incorrectly handled CMP protection algorithm validation. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2026-63076) It was discovered that OpenSSL incorrectly verified authentication tags when using certain AEAD ciphers via the EVP_Cipher() interface. An attacker could possibly use this issue to perform AEAD forgery attacks. (CVE-2026-75803)

Multiple security issues were discovered in MySQL. MySQL has been updated to 8.4.11 in Ubuntu 26.04 LTS. Ubuntu 22.04 LTS and Ubuntu 24.04 LTS packages have been updated with backported patches. In addition to security fixes, the updated packages contain bug fixes, new features, and possibly incompatible changes. Please see the following for more information: https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-11.html https://www.oracle.com/security-alerts/cpujul2026.html

It was discovered that libssh had a stack buffer overflow in its SFTP server when constructing directory listing entries for long filenames. An attacker could possibly use this issue to cause libssh to crash or execute arbitrary code. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-15370) It was discovered that libssh did not correctly handle SSH channel open messages advertising a zero maximum packet size. An authenticated remote attacker could possibly use this issue to cause libssh to consume excessive CPU resources, leading to a denial of service. (CVE-2026-59843) It was discovered that libssh did not correctly limit SFTP read request lengths in its server implementation. An authenticated remote attacker could possibly use this issue to cause libssh to allocate excessive memory, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-59844) It was discovered that libssh did not correctly handle ProxyCommand fork() failures. A local attacker could possibly use this issue to cause a denial of service. (CVE-2026-59845) It was discovered that libssh did not correctly sanitize shell metacharacters when expanding usernames in ProxyCommand strings. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-59846) It was discovered that libssh had incorrect AES-GCM tag verification when built with the OpenSSL backend. A machine-in-the-middle attacker could possibly use this issue to modify encrypted traffic without detection. (CVE-2026-59847) It was discovered that libssh did not correctly handle SFTP server responses for unknown request IDs. An attacker could possibly use this issue to cause libssh to use excessive memory, leading to a denial of service. (CVE-2026-59848) It was discovered that libssh had logic errors in certificate-based authentication that could cause clients to loop indefinitely when certificates were rejected. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-59849) It was discovered that libssh could invoke data callbacks on channels after they had been closed. An attacker could possibly use this issue to cause libssh to crash or execute arbitrary code. (CVE-2026-59850)

It was discovered that FreeRDP contained multiple security issues. An attacker could possibly use these issues to obtain sensitive information, cause FreeRDP to crash, resulting in a denial of service, or execute arbitrary code.

It was discovered that GNU Core Utilities sort had a heap buffer under-read in its begfield() function. A local attacker could possibly use this issue to cause GNU Core Utilities to crash, resulting in a denial of service, or obtain sensitive information. (CVE-2025-5278) It was discovered that GNU Core Utilities uniq had an out-of-bounds read when the -w option was used with crafted multibyte input. A local attacker could possibly use this issue to cause GNU Core Utilities to crash, resulting in a denial of service, or obtain sensitive information. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-56391)

It was discovered that Bind incorrectly handled DNSSEC validation when a domain was covered by both NSEC and NSEC3 records with only one type having an RRSIG. A remote attacker could possibly use this issue to cause Bind to crash, resulting in a denial of service.

It was discovered that the JSSE component of OpenJDK 26 did not correctly authenticate users. A remote attacker could possibly use this issue to read or modify sensitive data. (CVE-2026-46968) It was discovered that the JSSE component of OpenJDK 26 did not correctly authorize users. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-46917) It was discovered that the ImageIO component of OpenJDK 26 did not correctly authorize users. A remote attacker could possibly use this issue to read or modify sensitive data. (CVE-2026-47010) It was discovered that the 2D component of OpenJDK 26 did not correctly authorize users. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-47021, CVE-2026-47059) It was discovered that the Libraries component of OpenJDK 26 did not correctly authorize users. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-47027) It was discovered that the Security component of OpenJDK 26 did not correctly authenticate users. A remote attacker could possibly use this issue to read or modify sensitive data. (CVE-2026-60147) It was discovered that the Libraries component of OpenJDK 26 did not correctly authenticate users. A remote attacker could possibly use this issue to read or modify sensitive data. (CVE-2026-47063) Lian Owen discovered that the 2D (Little CMS) component of OpenJDK 26 did not correctly handle certain integer arithmetic. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-41254)

Siebe Devroe, Héloïse Gollier, and Mathy Vanhoef discovered that the WiFi implementation in the Linux kernel did not properly handle aggregated frames in mesh networks, due to an incorrect fix for CVE-2020-24588. A physically proximate attacker could use this issue to inject packets. (CVE-2025-27558) Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - x86 architecture; - Cryptographic API; - InfiniBand drivers; - Media drivers; - NVIDIA Tegra memory controller driver; - Network drivers; - NVME drivers; - File systems infrastructure; - Ext4 file system; - IPv4 networking; - Network traffic control; - TCP network protocol; - Locking primitives; - B.A.T.M.A.N. meshing protocol; - Ceph Core library; - IPv6 networking; - Multipath TCP; - Netfilter; - SCTP protocol; - SMC sockets; - TIPC protocol; (CVE-2021-47378, CVE-2026-23392, CVE-2026-31405, CVE-2026-31414, CVE-2026-31448, CVE-2026-31657, CVE-2026-31668, CVE-2026-43071, CVE-2026-43198, CVE-2026-43493, CVE-2026-43499, CVE-2026-46266, CVE-2026-46331, CVE-2026-52914, CVE-2026-52924, CVE-2026-52931, CVE-2026-52955, CVE-2026-52958, CVE-2026-52982, CVE-2026-52986, CVE-2026-52989, CVE-2026-52993, CVE-2026-52999, CVE-2026-53002, CVE-2026-53006, CVE-2026-53045, CVE-2026-53088, CVE-2026-53176, CVE-2026-53212, CVE-2026-53228, CVE-2026-53359)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - File systems infrastructure; - OCFS2 file system; - B.A.T.M.A.N. meshing protocol; - SCTP protocol; - TIPC protocol; (CVE-2026-43071, CVE-2026-52914, CVE-2026-52993, CVE-2026-53043, CVE-2026-53224, CVE-2026-53246, CVE-2026-53309)

Siebe Devroe, Héloïse Gollier, and Mathy Vanhoef discovered that the WiFi implementation in the Linux kernel did not properly handle aggregated frames in mesh networks, due to an incorrect fix for CVE-2020-24588. A physically proximate attacker could use this issue to inject packets. (CVE-2025-27558) Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - x86 architecture; - InfiniBand drivers; - Network drivers; - NVME drivers; - Ext4 file system; - SMB network file system; - IPv4 networking; - Network traffic control; - TCP network protocol; - Locking primitives; - IPv6 networking; - Multipath TCP; - Netfilter; - Open vSwitch; - SCTP protocol; - SMC sockets; (CVE-2026-31414, CVE-2026-31448, CVE-2026-31705, CVE-2026-43198, CVE-2026-43378, CVE-2026-43499, CVE-2026-46266, CVE-2026-46331, CVE-2026-52924, CVE-2026-52989, CVE-2026-53086, CVE-2026-53176, CVE-2026-53212, CVE-2026-53215, CVE-2026-53224, CVE-2026-53225, CVE-2026-53228, CVE-2026-53246, CVE-2026-53359, CVE-2026-64531)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - Open vSwitch; - SCTP protocol; (CVE-2026-53224, CVE-2026-53246, CVE-2026-64531)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - Network drivers; - Open vSwitch; - SCTP protocol; (CVE-2026-53224, CVE-2026-53246, CVE-2026-53247, CVE-2026-64531)

Juthawong Naisanguansee discovered that PAM incorrectly cleared failed login attempt records when certain services invoked the account phase without first performing authentication. An attacker could possibly use this issue to reset failed login counters, resulting in authentication lockout restrictions being bypassed.

It was discovered that p11-kit incorrectly handled certain RPC messages. A local attacker could use this issue to cause p11-kit to crash, resulting in a denial of service. (CVE-2026-13757) It was discovered that p11-kit incorrectly handled nested attribute decoding on 32-bit systems. A local attacker could use this issue to cause p11-kit to crash, resulting in a denial of service. (CVE-2026-18938)

It was discovered that primitive decoders in openCryptoki produced integer underflows when the encoded length was zero. An attacker could possibly use this issue to trigger out-of-bounds reads. (CVE-2026-40253) It was discovered that openCryptoki incorrectly handled symlinks. An attacker in the token-group could possibly use this issue to achieve privilege escalation or access sensitive information. (CVE-2026-23893)