https://ubuntu.com/security/notices/rss.xmlRecent content on Ubuntu security notices2026 Canonical Ltd. Ubuntu and Canonical are registered trademarks of Canonical Ltd.http://www.rssboard.org/rss-specificationFeedgenWed, 21 Oct 2026 01:10:46 +0000https://ubuntu.com/security/notices/USN-8945-1It was discovered that XZ Utils incorrectly handled certain memory allocation failures when reinitializing decoders for specific compressed file formats. An attacker could possibly use this issue to trigger an invalid memory write, resulting in a denial of service or arbitrary code execution.https://ubuntu.com/security/notices/USN-8945-1Tue, 20 Oct 2026 17:45:10 +0000https://ubuntu.com/security/notices/USN-8944-1This update removes the "emSign ECC Root CA - G3" CA certificate due to intermediate CA certificates being compromised. In addition, in Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS, the ca-certificates package contained outdated CA certificates. This update refreshes the included certificates to those contained in the 2.90 version of the Mozilla certificate authority bundle.https://ubuntu.com/security/notices/USN-8944-1Tue, 20 Oct 2026 15:52:06 +0000https://ubuntu.com/security/notices/USN-8942-1Multiple security issues were discovered in .NET and this update includes new upstream .NET versions to fix these issues. .NET 8 has been updated to 8.0.32 in Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. .NET 10 has been updated to 10.0.13 in Ubuntu 24.04 LTS, Ubuntu 26.04 LTS and Ubuntu 26.10. .NET 11 has been updated to 11.0.0~rc2 in Ubuntu 26.10. In addition to security fixes, the updated packages contain bug fixes, new features, and possibly incompatible changes.https://ubuntu.com/security/notices/USN-8942-1Tue, 20 Oct 2026 15:15:07 +0000https://ubuntu.com/security/notices/USN-8943-1It was discovered that Protocol Buffers did not properly handle negative varint lengths or enforce recursion limits when parsing input in the PHP library. An attacker could possibly use this issue to cause applications using Protocol Buffers to crash or consume resources, resulting in a denial of service.https://ubuntu.com/security/notices/USN-8943-1Tue, 20 Oct 2026 14:49:32 +0000https://ubuntu.com/security/notices/USN-8708-2USN-8708-1 fixed a vulnerability in sudo-rs. This update provides the corresponding fix for Ubuntu 26.10. Original advisory details: 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.https://ubuntu.com/security/notices/USN-8708-2Tue, 20 Oct 2026 14:23:39 +0000https://ubuntu.com/security/notices/USN-8941-1It was discovered that Squid incorrectly handled certain HTTP Transfer- Encoding headers. An attacker could possibly use this issue to perform HTTP request smuggling attacks, bypass security mechanisms, or poison web caches. (CVE-2026-61642) It was discovered that Squid incorrectly handled certain cache digest replies, which could lead to a buffer overflow. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-50012) It was discovered that Squid incorrectly handled parsing certain FTP directory listings. A remote attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-47729) It was discovered that Squid incorrectly handled certain ICP traffic. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-32748, CVE-2026-33526) It was discovered that Squid incorrectly handled certain ICP requests. A remote attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-33515)https://ubuntu.com/security/notices/USN-8941-1Tue, 20 Oct 2026 13:59:52 +0000https://ubuntu.com/security/notices/USN-8940-1It was discovered that the Perl XS::Parse::Keyword module did not correctly handle certain inputs. If a user or automated system were tricked into receiving specially crafted input, an attacker could cause a denial of service.https://ubuntu.com/security/notices/USN-8940-1Tue, 20 Oct 2026 03:21:29 +0000https://ubuntu.com/security/notices/USN-8939-1It was discovered that libXtst did not properly handle certain RECORD replies from the X server. A malicious X server could possibly use this issue to cause libXtst clients to crash, resulting in a denial of service. (CVE-2026-94286) Tobias Stoeckmann discovered that libXtst did not properly handle certain memory operations. A malicious X server could possibly use this issue to cause libXtst to access memory out of bounds, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2016-7951) Tobias Stoeckmann discovered that libXtst did not properly handle certain replies from the X server. A malicious X server could possibly use this issue to cause libXtst to enter an infinite loop, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2016-7952)https://ubuntu.com/security/notices/USN-8939-1Mon, 19 Oct 2026 17:17:18 +0000https://ubuntu.com/security/notices/USN-8927-2USN-8927-1 fixed vulnerabilities in curl. This update provides the corresponding fixes for Ubuntu 26.10. Original advisory details: It was discovered that curl, when built with GnuTLS support, had an out-of-bounds read in the WebSocket send path. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-107928) Maksim discovered that curl did not correctly include the interface binding in connection reuse decisions when CURLOPT_INTERFACE was used. An attacker could possibly use this issue to cause connections to go out from an unintended source address. (CVE-2026-107929) Stanislav Fort discovered that curl did not properly clear AWS SigV4 authentication state when CURLOPT_AWS_SIGV4 was set to NULL. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-86409) Stanislav Fort discovered that the curl command line tool did not set SSH host verification options when following redirects to SFTP or SCP URLs. An attacker could possibly use this issue to perform machine-in-the-middle attacks. (CVE-2026-86410) Stanislav Fort discovered that curl did not properly handle cookie jar entries that could not be reloaded. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-86412) Stanislav Fort discovered that an HTTP proxy could trick libcurl into sending credentials to the proxy itself by responding to a CONNECT request with an unexpected authentication challenge. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-86414) Stanislav Fort discovered that curl did not correctly handle HSTS entries when an includeSubDomains parent entry was imported before a longer-lived child entry. An attacker could possibly use this issue to cause curl to use unencrypted HTTP connections. (CVE-2026-87862) Stanislav Fort discovered that curl did not properly handle HSTS max-age values that exceeded calendar time structure bounds. An attacker could possibly use this issue to cause a denial of service or data loss. (CVE-2026-87863) Stanislav Fort discovered that curl did not properly handle IMAP APPEND commands when CURLOPT_CRLF was enabled, allowing overflow bytes to be interpreted as pipelined commands. An authenticated attacker could possibly use this issue to inject arbitrary IMAP commands. (CVE-2026-87864) Bobbeh Rhino discovered that libcurl, when used with libssh2 and a hashed known_hosts file, could misreport a host key mismatch as a missing key. An attacker could possibly use this issue to perform machine-in-the-middle attacks. (CVE-2026-87865) Joshua Rogers discovered that curl did not properly handle long cookie entries written to a Netscape cookie jar. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-92386) Joshua Rogers discovered that a malicious FTP, IMAP, POP3, or SMTP server could cause libcurl to block indefinitely by omitting the final control-response line. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-92387) Joshua Rogers discovered that libcurl had a use-after-free vulnerability in the FTP wildcard matching code. An attacker could possibly use this issue to cause curl to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-92388) Joshua Rogers discovered that libcurl's TFTP state machine did not properly validate transfer directions, allowing a malicious server to force the client into transmit mode. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-92389) Joshua Rogers discovered that curl did not properly enforce its file overwrite protection when using --remote-header-name in certain circumstances. An attacker could possibly use this issue to overwrite local files. (CVE-2026-92390) Joshua Rogers discovered that curl had a stack overflow vulnerability when processing deeply nested MIME structures. An attacker could possibly use this issue to cause curl to crash, resulting in a denial of service. (CVE-2026-92391) Joshua Rogers discovered that libcurl could expose credentials in the URL returned by CURLINFO_EFFECTIVE_URL when credentials were retrieved from a .netrc file. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-94266) Joshua Rogers discovered that libcurl had a use-after-free vulnerability during HTTP/2 uploads when handling RST_STREAM responses from the server. An attacker could possibly use this issue to cause curl to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-92392)https://ubuntu.com/security/notices/USN-8927-2Mon, 19 Oct 2026 15:51:17 +0000https://ubuntu.com/security/notices/USN-8938-1It was discovered that cifs-utils incorrectly handled credentials files used by privileged mount.cifs invocations. A local attacker could possibly use this issue to inject arbitrary mount options into a privileged mount, resulting in a privilege escalation.https://ubuntu.com/security/notices/USN-8938-1Mon, 19 Oct 2026 13:56:50 +0000