Ubuntu Security Advisories

USN-8890-1 fixed vulnerabilities in libsoup. This update provides the corresponding updates for libsoup3 on Ubuntu 26.10. Original advisory details: It was discovered that libsoup incorrectly handled certain HTTP/2 requests. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-4271) It was discovered that libsoup incorrectly handled certain HTTPS proxy connections. A remote attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-5119) It was discovered that libsoup incorrectly parsed certain chunked HTTP requests. A remote attacker could possibly use this issue to bypass security controls. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-6324) It was discovered that libsoup incorrectly handled proxy authentication credentials. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-66339) It was discovered that libsoup incorrectly handled certain HTTP Range headers. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-77014, CVE-2026-77680) It was discovered that libsoup incorrectly handled certain HTTP/2 connections. A remote attacker could possibly use this issue to obtain sensitive information or execute arbitrary code. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-85197) It was discovered that libsoup incorrectly handled certain HTTP/2 transfers. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-85534)

It was discovered that c-ares incorrectly parsed certain SOA replies. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-22217) It was discovered that c-ares incorrectly handled certain sortlist strings. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service, or execute arbitrary code. This issue only affected Ubuntu 16.04 LTS. (CVE-2022-4904) It was discovered that c-ares did not properly limit DNS compression pointer hops or assembled name lengths when parsing DNS names. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. (CVE-2026-69184) It was discovered that c-ares did not properly validate record count fields before allocating memory when parsing DNS responses. A remote attacker could possibly use this issue to cause c-ares to use excessive resources, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-69186)

This update removes the "emSign ECC Root CA - G3" and "Comodo AAA Services root" CA certificate due to intermediate CA certificates being compromised.

It was discovered that poppler incorrectly handled the password length limit when decrypting certain encrypted PDF files. An attacker could possibly use this issue to cause a denial of service.

USN-8930-1 fixed some vulnerabilities in U-Boot. This update provides the corresponding fix for U-Boot on Ubuntu 26.10. Original advisory details: Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot incorrectly handled certain NFS READ and NFS READLINK responses. An attacker could possibly use this issue to trigger a buffer overflow, resulting in a denial of service or arbitrary code execution. (CVE-2026-74220, CVE-2026-74221) Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot incorrectly handled certain HTTP data storage failures in its lwIP implementation. An attacker could possibly use this issue to trigger a use-after-free, resulting in a denial of service. (CVE-2026-74222) Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot did not properly validate certain DHCPv6 option lengths during network boot. An attacker could possibly use this issue to trigger out-of-bounds memory access, resulting in a denial of service. (CVE-2026-74225)

Rick de Jager discovered that Ghostscript incorrectly handled memory under certain circumstances when processing PostScript documents. If a user or automated system were tricked into processing a specially crafted document, an attacker could possibly use this issue to bypass the sandbox and execute arbitrary code. (CVE-2026-101258) It was discovered that Ghostscript incorrectly handled memory when converting certain fonts. If a user or automated system were tricked into processing a specially crafted file, an attacker could possibly use this issue to cause Ghostscript to crash, or possibly execute arbitrary code. (CVE-2026-103226) Paulos Yibelo discovered that Ghostscript did not properly validate certain operands when loading fonts. If a user or automated system were tricked into processing a specially crafted file, an attacker could possibly use this issue to bypass the sandbox and execute arbitrary code. (No CVE number)

USN-8948-1 fixed vulnerabilities in Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 26.04 LTS and Ubuntu 26.10. This provides the corrosponding updates in Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. Original advisory details: It was discovered that PHP incorrectly handled out-of-memory conditions while processing requests. A remote attacker could use this issue to execute arbitrary code. (CVE-2026-109618) It was discovered that PHP incorrectly managed internal request state across worker reuse. A remote attacker could use this issue to execute arbitrary code. (CVE-2026-109619)

It was discovered that PHP incorrectly handled out-of-memory conditions while processing requests. A remote attacker could use this issue to execute arbitrary code. (CVE-2026-109618) It was discovered that PHP incorrectly managed internal request state across worker reuse. A remote attacker could use this issue to execute arbitrary code. (CVE-2026-109619)

It was discovered that Unbound incorrectly handled certain TCP connections. A remote attacker could possibly use this issue to cause Unbound to consume resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS, Ubuntu 24.04 LTS, Ubuntu 22.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-80225) It was discovered that Unbound incorrectly handled certain DNS responses. A remote attacker could possibly use this issue to crash Unbound, resulting in a denial of service. (CVE-2026-81634) It was discovered that Unbound incorrectly handled certain DNS responses during DNSSEC validation. A remote attacker could possibly use this issue to cause Unbound to consume resources, leading to a denial of service. (CVE-2026-85501) It was discovered that Unbound incorrectly handled outgoing network ports. A remote attacker could possibly use this issue to crash Unbound, resulting in a denial of service. (CVE-2026-50252) It was discovered that Unbound incorrectly handled certain DNSCrypt packets. A remote attacker could possibly use this issue to crash Unbound, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS, Ubuntu 24.04 LTS, Ubuntu 22.04 LTS, Ubuntu 20.04 LTS and Ubuntu 18.04 LTS. (CVE-2026-40691) It was discovered that Unbound incorrectly handled certain cached DNS responses. A remote attacker could possibly use this issue to poison Unbound's cache. This issue only affected Ubuntu 26.04 LTS, Ubuntu 24.04 LTS, Ubuntu 22.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-44690) It was discovered that Unbound incorrectly handled certain DNS-over-QUIC connections. A remote attacker could possibly use this issue to cause Unbound to consume resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-32665) It was discovered that Unbound incorrectly handled certain EDNS options. A remote attacker could possibly use this issue to crash Unbound, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-55973) Elias Heftrig, Haya Schulmann, Niklas Vogel, and Michael Waidner discovered that Unbound incorrectly handled validating DNSSEC messages. A remote attacker could possibly use this issue to cause Unbound to consume resources, leading to a denial of service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 16.04 LTS and Ubuntu 14.04 LTS. (CVE-2023-50387) It was discovered that Unbound incorrectly handled preparing an NSEC3 closest encloser proof. A remote attacker could possibly use this issue to cause Unbound to consume resources, leading to a denial of service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 16.04 LTS and Ubuntu 14.04 LTS. (CVE-2023-50868)

USN-8944-1 updated ca-certificates. This update provides the corresponding changes for Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS by removing the "emSign ECC Root CA - G3" and "Comodo AAA Services root" CA certificates. Original advisory details: This 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.

It 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.

This 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.

Multiple 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.

It 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.

USN-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.

It 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)

It 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.

It 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)

USN-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)

It 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.