Ubuntu Security Advisories

Eunsoo Kim discovered that curl incorrectly handled SASL negotiation for LDAP authentication in certain circumstances. A machine-in-the-middle attacker could possibly use this issue to bypass peer validation. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-13608) Stephan Zeisberg discovered that curl incorrectly handled HTTP/2 Server Push streams when sharing connections between handles. A remote attacker could possibly use this issue to cause curl to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-18924) Stanislav Fort discovered that curl incorrectly managed the lifetime of pooled TLS connections when using the multi interface. An attacker could possibly use this issue to cause curl to crash, resulting in a denial of service, or execute arbitrary code. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-80229) Stanislav Fort discovered that curl did not properly enforce public key pinning when certificate verification was disabled in certain circumstances. A remote attacker could possibly use this issue to bypass pinning checks and cause curl to accept connections that should have been rejected. (CVE-2026-80230) Stanislav Fort discovered that curl incorrectly handled the Secure attribute of cookies in certain circumstances. A remote attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-80255) Stanislav Fort discovered that curl did not properly enforce Public Suffix List boundaries when handling cookies in certain circumstances. A remote attacker could possibly use this issue to cause cookies to be sent to unrelated domains, resulting in sensitive information being exposed. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-82209) Ady Elouej discovered that curl did not clear proxy authentication state between requests when reusing a handle with environment-variable proxy configuration. A remote attacker could possibly use this issue to obtain sensitive credentials. This issue was previously fixed in USN-8487-1, but that fix was incomplete for Ubuntu 16.04 LTS. (CVE-2026-8927)

It was discovered that OpenStack Swift incorrectly handled truncated aws-chunked PUT request bodies in its s3api middleware. An authenticated attacker could possibly use this issue to cause OpenStack Swift to use excessive resources, leading to a denial of service.

It was discovered that some Arm processors could complete a broadcast translation lookaside buffer (TLB) invalidation before memory writes made through the invalidated translation were globally observed. A local attacker could possibly use this to write to memory after permission to do so had been revoked, bypassing memory protections or escalating privileges. (CVE-2025-10263) 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: - ARM64 architecture; - InfiniBand drivers; - Network drivers; - TCM subsystem; - exFAT file system; - Network file system (NFS) client; - Network file system (NFS) server daemon; - B.A.T.M.A.N. meshing protocol; - IPv4 networking; - IPv6 networking; - Netfilter; - RDS protocol; (CVE-2026-53186, CVE-2026-53216, CVE-2026-53221, CVE-2026-53354, CVE-2026-53355, CVE-2026-53398, CVE-2026-63800, CVE-2026-63808, CVE-2026-63887, CVE-2026-63888, CVE-2026-63912, CVE-2026-63922, CVE-2026-63924, CVE-2026-63984, CVE-2026-63992, CVE-2026-63993, CVE-2026-63994, CVE-2026-64007, CVE-2026-64091)

It was discovered that some Arm processors could complete a broadcast translation lookaside buffer (TLB) invalidation before memory writes made through the invalidated translation were globally observed. A local attacker could possibly use this to write to memory after permission to do so had been revoked, bypassing memory protections or escalating privileges. (CVE-2025-10263) 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: - ARM64 architecture; - InfiniBand drivers; - Network drivers; - TCM subsystem; - B.A.T.M.A.N. meshing protocol; - HSR network protocol; - IPv4 networking; - IPv6 networking; - Netfilter; - RDS protocol; (CVE-2026-53131, CVE-2026-53186, CVE-2026-53216, CVE-2026-53221, CVE-2026-53354, CVE-2026-53355, CVE-2026-63886, CVE-2026-63887, CVE-2026-63888, CVE-2026-63912, CVE-2026-63922, CVE-2026-63924, CVE-2026-63984, CVE-2026-63992, CVE-2026-63993, CVE-2026-63994, CVE-2026-64000, CVE-2026-64007, CVE-2026-64091)

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: - ARM64 architecture; - S390 architecture; - x86 architecture; - DRBD Distributed Replicated Block Device drivers; - InfiniBand drivers; - IOMMU subsystem; - Multiple devices driver; - Network drivers; - Microsoft Azure Network Adapter (MANA) driver; - NVME drivers; - TCM subsystem; - Virtio Host (VHOST) subsystem; - Xen hypervisor drivers; - AFS file system; - File systems infrastructure; - Network file systems library; - Network file system (NFS) client; - NTFS3 file system; - OCFS2 file system; - OrangeFS file system; - SMB network file system; - IPv4 networking; - Sun RPC protocol; - IPv6 networking; - IP tunnels definitions; - Netfilter; - TCP network protocol; - Locking primitives; - 9P file system network protocol; - B.A.T.M.A.N. meshing protocol; - Networking core; - IFE protocol; - RxRPC session sockets; - Network traffic control; - SCTP protocol; - SMC sockets; - TIPC protocol; - XFRM subsystem; (CVE-2026-64530, CVE-2026-64534, CVE-2026-64535, CVE-2026-64541, CVE-2026-64551, CVE-2026-68083, CVE-2026-68457, CVE-2026-68476, CVE-2026-68477, CVE-2026-72014, CVE-2026-72020, CVE-2026-72033, CVE-2026-72041, CVE-2026-72046, CVE-2026-72064, CVE-2026-72065, CVE-2026-72069, CVE-2026-72083, CVE-2026-72084, CVE-2026-72085, CVE-2026-72098, CVE-2026-72129, CVE-2026-72130, CVE-2026-72137, CVE-2026-72139, CVE-2026-72191, CVE-2026-72192, CVE-2026-72194, CVE-2026-72217, CVE-2026-72220, CVE-2026-72221, CVE-2026-72222, CVE-2026-72226, CVE-2026-72234, CVE-2026-72248, CVE-2026-72249, CVE-2026-72251, CVE-2026-72277, CVE-2026-72278, CVE-2026-72279, CVE-2026-72287, CVE-2026-72288, CVE-2026-72289, CVE-2026-72296, CVE-2026-72299, CVE-2026-72317, CVE-2026-72318, CVE-2026-72319, CVE-2026-72320, CVE-2026-72322, CVE-2026-72323, CVE-2026-72329, CVE-2026-72339, CVE-2026-72348, CVE-2026-72351, CVE-2026-72355, CVE-2026-72366, CVE-2026-72381, CVE-2026-72393, CVE-2026-72398, CVE-2026-72399, CVE-2026-72412, CVE-2026-72417, CVE-2026-72422, CVE-2026-72429, CVE-2026-72436, CVE-2026-72442, CVE-2026-72451, CVE-2026-72463, CVE-2026-72466, CVE-2026-72472, CVE-2026-72473, CVE-2026-72477, CVE-2026-72491, CVE-2026-72493, CVE-2026-72494, CVE-2026-72495, CVE-2026-72496, CVE-2026-72501, CVE-2026-74255, CVE-2026-74267, CVE-2026-74268, CVE-2026-74269, CVE-2026-74287, CVE-2026-74310, CVE-2026-74345, CVE-2026-74350, CVE-2026-74361, CVE-2026-74376, CVE-2026-74384, CVE-2026-74394, CVE-2026-74398, CVE-2026-74401, CVE-2026-74406, CVE-2026-74427, CVE-2026-74428, CVE-2026-74433, CVE-2026-74434, CVE-2026-74436, CVE-2026-74439, CVE-2026-80665)

It was discovered that libass incorrectly handled parsing operations for specific nested character strings. An attacker could use this issue to cause libass to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-24994) It was discovered that libass incorrectly handled certain outline processing operations. An attacker could use this issue to cause libass to crash, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-26682) It was discovered that libass incorrectly handled certain ASS subtitle files when measuring wrapped lines. An attacker could use this issue to cause libass to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-61627) It was discovered that libass incorrectly handled certain Matroska subtitle chunks with negative ReadOrder values. An attacker could use this issue to cause libass to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-61626)

It was discovered that Expat did not correctly handle certain integer arithmetic. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-56406, CVE-2026-56407, CVE-2026-56409, CVE-2026-56410, CVE-2026-56411) It was discovered that Expat did not correctly track handler call depth. An attacker could possibly use this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-56131) It was discovered that Expat did not correctly handle certain memory operations. An attacker could possibly use this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-56132) It was discovered that Expat did not correctly handle certain Unicode characters. An attacker could possibly use this issue to cause Expat to use excessive resources, leading to a denial of service. (CVE-2026-72522) It was discovered that Expat did not correctly process certain XML attributes. A remote attacker could possibly use this issue to cause Expat to use excessive resources, leading to a denial of service. (CVE-2026-66046) It was discovered that Expat did not correctly handle certain external entities. An attacker could possibly use this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-76641) It was discovered that Expat did not correctly track handler call depth with custom encodings. An attacker could possibly use this issue to cause Expat to crash or execute arbitrary code. (CVE-2026-76957)

It was discovered that Octavia did not properly validate TLS cipher string fields in the Amphora provider driver. An authenticated attacker who owns a TLS-enabled load balancer could possibly use this issue to inject arbitrary HAProxy configuration directives. (CVE-2026-94572) It was discovered that Octavia did not properly validate L7 policy redirect URL fields in the Amphora provider driver. An authenticated attacker who owns a load balancer could possibly use this issue to inject arbitrary HAProxy configuration directives. (CVE-2026-94571) It was discovered that Octavia incorrectly handled quality of service policy authorization. An authenticated attacker could possibly use this issue to prevent deletion of another project's QoS policy. (CVE-2026-74248)

It was discovered that GDAL incorrectly handled certain netCDF files. An attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-49014) It was discovered that GDAL incorrectly handled certain HDF-EOS files. An attacker could possibly use this issue to cause a crash or execute arbitrary code. (CVE-2026-8086, CVE-2026-8087, CVE-2026-8212, CVE-2026-8213) It was discovered that GDAL incorrectly handled certain HDF-EOS file metadata. An attacker could possibly use this issue to cause GDAL to crash, resulting in a denial of service. (CVE-2026-8084, CVE-2026-8088)

It was discovered that urllib3 did not correctly strip sensitive HTTP headers during cross-origin redirects. An attacker could possibly use this issue to leak sensitive information.

It was discovered that ImageMagick did not correctly handle certain memory operations. An attacker could possibly use this issue to cause a denial of service. This issue affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-33535) Kamil Frankowicz discovered that ImageMagick did not correctly handle certain memory operations. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. This issue affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-33536) It was discovered that ImageMagick did not correctly handle certain integer arithmetic. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-34238) Jake Lamberson discovered that ImageMagick did not correctly handle certain memory operations. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. This issue affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-40310) Junmin Zhu discovered that ImageMagick did not correctly handle certain memory operations. An attacker could possibly use this issue to cause a denial of service. This issue affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-40311) It was discovered that ImageMagick did not correctly handle opening certain MSL files. If a user or automated system were tricked into opening a specially crafted file, an attacker could possibly cause a denial of service. This issue affected Ubuntu 26.04 LTS. (CVE-2026-40312) It was discovered that ImageMagick did not correctly handle certain memory operations. An attacker could possibly use this issue to execute arbitrary code. (CVE-2026-56361)

USN-8287-1 fixed a vulnerability in XDG Desktop Portal. Unfortunately the fix for CVE-2026-40354 was incomplete and introduced a regression when trashing files. This update fixes the problem and provides the corresponding update for Ubuntu 26.04 LTS. We apologize for the inconvenience. Original advisory details: It was discovered that XDG Desktop Portal incorrectly handled trashing files. A local attacker could possibly use this issue to delete arbitrary files on the host file system via a symlink attack.

Kazuma Matsumoto and Isabel Mill discovered that libgit2 incorrectly handled certain repository URLs when using the SSH transport. A remote attacker could possibly use this issue to execute arbitrary commands.

It was discovered that SQL parse contained multiple algorithmic complexity flaws when parsing SQL statements with deeply nested parentheses, comments, or dollar-quoted string literals. An attacker could use this issue to cause SQL parse to consume excessive CPU resources, resulting in a denial of service.

It was discovered that Open-iSNS contained a double-free vulnerability when decoding malformed iSNS attributes. An unauthenticated attacker could possibly use this to cause a denial of service.

It was discovered that Moodle did not properly restrict URLs. An authenticated user could possibly use this issue to perform a server-side request forgery attack and expose sensitive information.

It was discovered that NetworkManager did not properly restrict the ca-path and phase2-ca-path certificate authority settings for private (single-user) 802.1X network connections. An attacker could use this issue to point their own private 802.1X connection profile at a directory under their control, causing NetworkManager to trust an attacker-chosen certificate authority and potentially exposing network credentials via a rogue authentication server.

USN-8733-1 fixed vulnerabilities in Gzip. This update provides the corresponding fix for Gzip on Ubuntu 14.04 LTS, Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. Original advisory details: Michał Majchrowicz and Marcin Wyczechowski discovered that Gzip's gzexe utility created temporary files in an insecure manner when mktemp was unavailable. A local attacker could possibly use this issue to overwrite arbitrary files. (CVE-2026-41991) Elias Hasas, Michał Majchrowicz and Marcin Wyczechowski discovered that Gzip incorrectly handled certain compressed files. An attacker could possibly use this issue to obtain sensitive information or cause Gzip to crash, resulting in a denial of service. (CVE-2026-41992)

Florian Kohnhäuser discovered that OpenSSH incorrectly handled shell metacharacters in certain usernames. An attacker could possibly use this issue to execute arbitrary commands when certain non-default configurations were used, resulting in arbitrary code execution. This issue only affected Ubuntu 14.04 LTS. (CVE-2026-35386) Christos Papakonstantinou discovered that OpenSSH incorrectly handled ECDSA algorithm restrictions. An attacker could possibly use this issue to cause unintended ECDSA algorithms to be accepted, resulting in security restrictions being bypassed. (CVE-2026-35387) Vladimir Tokarev discovered that OpenSSH incorrectly handled certain principal restrictions in authorized_keys files. An attacker could possibly use this issue to bypass principal restrictions, resulting in unauthorized access. This issue only affected Ubuntu 14.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-35414) It was discovered that OpenSSH incorrectly handled downloaded file paths when using sftp with an untrusted server. An attacker could possibly use this issue to write downloaded files outside the intended location, resulting in unauthorized file modification. (CVE-2026-59995) It was discovered that OpenSSH incorrectly handled command-line arguments in internal-sftp. An attacker could possibly use this issue to cause certain security-related arguments to be ignored, resulting in security restrictions being bypassed. (CVE-2026-59997) It was discovered that OpenSSH incorrectly handled GSSAPIStrictAcceptorCheck when used with Windows Active Directory. An attacker could possibly use this issue to bypass GSSAPI security restrictions, resulting in unauthorized access. (CVE-2026-59998) It was discovered that OpenSSH incorrectly handled forwarding restrictions when DisableForwarding and PermitTunnel were used together. An attacker could possibly use this issue to create tunnels despite forwarding being disabled, resulting in security restrictions being bypassed. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-59999) It was discovered that OpenSSH incorrectly handled authentication attempt limits when using GSSAPI authentication. An attacker could possibly use this issue to consume excessive system resources, resulting in a denial of service. (CVE-2026-60000) It was discovered that OpenSSH did not always enforce the minimum authentication delay. An attacker could possibly use this issue to perform authentication attempts more rapidly than intended, resulting in weakened brute-force protections. This issue only affected Ubuntu 20.04 LTS. (CVE-2026-60001) It was discovered that OpenSSH incorrectly handled certain concurrent remote forwarding operations. An attacker could possibly use this issue to trigger a use-after-free, resulting in a denial of service or arbitrary code execution. (CVE-2026-73282)

Guannan Wang, Zhanpeng Liu, and Guancheng Li discovered that Sudo failed to apply intercept policy checks when commands were executed under certain circumstances. A local attacker permitted to run specific commands could possibly use this issue to bypass policy enforcement and logging, executing unauthorized programs.