Ubuntu Security Advisories

It was discovered that the rabbitmq-c command-line tools only accepted credentials on the command line, making them visible to other local users through the process list. An attacker could possibly use this to obtain sensitive credentials. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2023-35789) It was discovered that rabbitmq-c did not correctly compute AMQP frame lengths, leading to a size_t underflow. A remote attacker could possibly use this to cause rabbitmq-c to crash, resulting in a denial of service, or possibly expose sensitive information. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-44235) It was discovered that rabbitmq-c did not properly validate the frame size during the AMQP login handshake. A remote attacker could possibly use this to cause a heap buffer overflow, resulting in a denial of service or possibly the execution of arbitrary code. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-44236) It was discovered that rabbitmq-c did not correctly validate the length of decoded bytes fields, leading to an integer overflow in a bounds check on 32-bit systems. A remote attacker controlling a broker, or able to intercept an unencrypted connection, could possibly use this to cause an out-of-bounds read, resulting in a denial of service or the exposure of sensitive information. (CVE-2026-59986) It was discovered that rabbitmq-c did not validate the body fragment length when serialising an AMQP body frame with the amqp_send_frame() API. An attacker could possibly use this to cause a heap buffer overflow, resulting in a denial of service (application crash) or possibly the execution of arbitrary code. This issue did not affect Ubuntu 14.04 LTS. (CVE-2026-61547)

It was discovered that GnuPG incorrectly validated authentication tag lengths when parsing CMS messages encrypted with AES-GCM. An attacker could possibly use this issue to bypass message integrity checks.

It was discovered that SPICE vdagent had an integer overflow in the buffer size calculation used when writing to the daemon socket. A malicious or compromised SPICE host could possibly use this issue to cause SPICE vdagent to crash, resulting in a denial of service. (CVE-2026-57965) It was discovered that SPICE vdagent did not properly sanitize filenames provided by the SPICE host during file transfers. A malicious or compromised SPICE host could possibly use this issue to write arbitrary files to any location on the guest operating system with the privileges of the spice-vdagent process. (CVE-2026-57966)

It was discovered that libssh2 incorrectly handled certain SFTP server responses. A remote attacker controlling an SSH server could use this issue to cause libssh2 to crash or possibly execute arbitrary code. (CVE-2026-66032) It was discovered that libssh2 incorrectly handled AES-GCM cipher negotiation. A remote attacker controlling an SSH server could possibly use this issue to cause libssh2 to crash, resulting in a denial of service. (CVE-2026-66033) It was discovered that libssh2 incorrectly handled Encrypt-then-MAC cipher negotiation. A remote attacker controlling an SSH server could use this issue to cause libssh2 to crash or possibly execute arbitrary code. (CVE-2026-66035)

It was discovered that APR-util incorrectly performed password hash comparisons in a way that was not constant-time. An attacker could possibly use this issue to obtain sensitive information. (CVE-2025-49506) It was discovered that APR-util incorrectly handled recursive XML element quoting. An attacker could possibly use this issue to cause applications using APR-util to crash, resulting in a denial of service. (CVE-2026-32327) It was discovered that the APR-util Redis client incorrectly handled certain network data, resulting in a heap-based buffer overflow. A remote attacker could possibly use this issue to cause APR-util applications to crash or execute arbitrary code. 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-2026-34501) It was discovered that the APR-util memcached client incorrectly handled certain network data, resulting in a heap-based buffer overflow. A remote attacker could possibly use this issue to cause APR-util applications to crash or execute arbitrary code. (CVE-2026-34502)

It was discovered that OpenSSH's ssh-agent incorrectly handled interactions between agent locking and the session-bind@openssh.com extension. A remote attacker with access to a forwarded agent connection could possibly use this issue to perform operations that should only be available locally, such as adding tokens or using keys. (CVE-2026-73281) It was discovered that OpenSSH's ssh client incorrectly handled concurrent remote-forwarding operations. A remote attacker could possibly use this issue to cause a use-after-free condition, resulting in a denial of service or the execution of arbitrary code. (CVE-2026-73282) It was discovered that OpenSSH's sshd server incorrectly applied the restrict keyword from authorized_keys to tunnel forwarding requests. A local attacker with an authorized key could possibly use this issue to bypass intended tunnel forwarding restrictions. (CVE-2026-73283)

It was discovered that SSSD did not properly validate authentication token lengths when processing PAM responder requests. A local attacker could possibly use this issue to cause SSSD to crash, resulting in a denial of service.

It was discovered that FFmpeg incorrectly handled certain crafted media files in the VobSub subtitle demuxer. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-64830) It was discovered that FFmpeg incorrectly handled certain crafted DTS audio streams in the S/PDIF muxer. An attacker could possibly use this issue to cause a denial of service or expose sensitive information. (CVE-2026-64833) It was discovered that FFmpeg incorrectly handled certain crafted RTP/ASF streams. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-64834) It was discovered that FFmpeg incorrectly handled certain crafted ADX audio files. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-64835) It was discovered that FFmpeg incorrectly handled certain crafted AVI files in the TDSC video decoder. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-65703) It was discovered that FFmpeg incorrectly handled certain crafted ffconcat files processed via the TY demuxer. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, and Ubuntu 24.04 LTS. (CVE-2026-65704) It was discovered that FFmpeg incorrectly handled certain crafted video streams in the vf_floodfill video filter. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, and Ubuntu 24.04 LTS. (CVE-2026-65705) It was discovered that FFmpeg incorrectly handled certain crafted NV12 video frames in the vf_swaprect video filter. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, and Ubuntu 24.04 LTS. (CVE-2026-65706) It was discovered that FFmpeg incorrectly handled certain crafted hvcC NAL arrays in the HEVC parser. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-75141) It was discovered that FFmpeg incorrectly handled certain crafted MPEG system headers. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-75142) It was discovered that FFmpeg incorrectly handled certain crafted network input in the librist protocol handler. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-75143) It was discovered that FFmpeg incorrectly handled certain crafted Dirac data units in the VC2 HQ RTP packetizer. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-75144) It was discovered that FFmpeg incorrectly handled certain crafted DASH manifests. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, and Ubuntu 24.04 LTS. (CVE-2026-75146)

It was discovered that Apache Tika's ISA-Tab parser incorrectly handled file path resolution. An attacker who could place files in a directory that Tika subsequently parses could use this issue to read arbitrary files accessible to the Tika process and have their contents emitted into the extracted text output.

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)

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; - OCFS2 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-2026-53043, CVE-2026-53045, CVE-2026-53088, CVE-2026-53176, CVE-2026-53212, CVE-2026-53224, CVE-2026-53225, CVE-2026-53228, CVE-2026-53246, CVE-2026-53309, 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: - OCFS2 file system; - SCTP protocol; (CVE-2026-53043, CVE-2026-53224, CVE-2026-53225, CVE-2026-53246, CVE-2026-53309)

Mark Bereza and Lilith Wyatt discovered that BioSig incorrectly handled certain crafted input files. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-22891, CVE-2026-20777)

It was discovered that pyasn1 did not properly bound the size of long-form tag identifiers when parsing BER, CER, or DER encoded data. An attacker could possibly use this issue to cause applications decoding untrusted ASN.1 data to consume excessive CPU resources, resulting in a denial of service. (CVE-2026-59884) It was discovered that pyasn1 processed OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs. An attacker could possibly use this issue to cause applications decoding untrusted ASN.1 data to consume excessive CPU resources, resulting in a denial of service. (CVE-2026-59885) It was discovered that pyasn1 incorrectly handled conversion of decoded REAL values to Python float types. An attacker could possibly use this issue to cause applications decoding untrusted ASN.1 data to consume excessive CPU and memory resources, resulting in a denial of service. (CVE-2026-59886)

It was discovered that Libgcrypt had a timing-based side-channel flaw in its RSA implementation. A remote attacker could possibly use this issue to obtain sensitive information.

USN-8688-1 fixed a vulnerability in PAM. This update provides the corresponding fix for PAM on Ubuntu 26.04 LTS. Original advisory details: 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.

USN-8555-1 fixed vulnerabilities in Ubuntu Advantage Tools. On Ubuntu 14.04 LTS only, it was discovered that some machines were unable to enable esm-infra-legacy due to a preemptive apt-helper check. This update fixes the problem. We apologize for the inconvenience. Original advisory details: Bilal Teke discovered that Ubuntu Advantage Tools exposed the Pro bearer token in command-line arguments when validating APT credentials. A local attacker could possibly use this issue to obtain sensitive information and gain unauthorized access to Ubuntu Pro repositories. (CVE-2026-9494) Frederick Jerusha discovered that Ubuntu Advantage Tools did not properly validate data received from the contract server when writing APT source files. An attacker could possibly use this issue to inject arbitrary APT configuration and execute arbitrary code. (CVE-2026-11386) Mateusz Gierblinski discovered that Ubuntu Advantage Tools did not properly handle symbolic links when collecting diagnostic logs. A local attacker could possibly use this issue to obtain sensitive information from files owned by the administrator. This issue only 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-2026-12391)

Alexis Challande discovered that libevent incorrectly handled certain empty output buffers. An attacker could possibly use this issue to trigger a use-after-free, resulting in a denial of service or arbitrary code execution. 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-2026-63381) Rajat Raghav discovered that libevent incorrectly handled certain HTTP requests. An attacker could possibly use this issue to desynchronize HTTP request boundaries, resulting in HTTP request smuggling. (CVE-2026-63382) Qiu Sihao discovered that libevent incorrectly handled certain malformed tagged RPC data. An attacker could possibly use this issue to trigger an out-of-bounds read, resulting in a denial of service. (CVE-2026-63383) Qiu Sihao discovered that libevent incorrectly handled certain large payload lengths in tagged RPC data. An attacker could possibly use this issue to consume excessive system resources, resulting in a denial of service. (CVE-2026-63384) Asaf Meizner discovered that libevent incorrectly handled certain HTTP URIs and header values. An attacker could possibly use this issue to cause HTTP messages to be interpreted inconsistently, resulting in security restrictions being bypassed. (CVE-2026-63385)

It was discovered that ncurses incorrectly handled specially crafted terminfo database entries. A local attacker could possibly use this issue to cause applications using ncurses to crash, resulting in a denial of service.

It was discovered that sudo-rs incorrectly handled time-of-check vs time- of-use conditions in sudoedit. A local attacker with permission to edit specific files using sudoedit could use this issue to place files in arbitrary directories, and possibly escalate their privileges. This issue only affected systems configured to grant fine-grained sudoedit file editing permissions, which is not the default configuration.