{"id":"UBUNTU-CVE-2026-41651","details":"PackageKit is a a D-Bus abstraction layer that allows the user to manage packages in a secure way using a cross-distro, cross-architecture API. PackageKit between and including versions 1.0.2 and 1.3.4 is vulnerable to a time-of-check time-of-use (TOCTOU) race condition on transaction flags that allows unprivileged users to install packages as root and thus leads to a local privilege escalation. This is patched in version 1.3.5. A local unprivileged user can install arbitrary RPM packages as root, including executing RPM scriptlets, without authentication. The vulnerability is a TOCTOU race condition on `transaction-\u003ecached_transaction_flags`  combined with a silent state-machine guard that discards illegal backward transitions while leaving corrupted flags in place. Three bugs exist in `src/pk-transaction.c`: 1. Unconditional flag overwrite (line 4036): `InstallFiles()` writes caller-supplied flags to `transaction-\u003ecached_transaction_flags` without checking whether the transaction has already been  authorized/started. A second call blindly overwrites the flags even while the transaction is RUNNING. 2. Silent state-transition rejection (lines 873–882): `pk_transaction_set_state()` silently discards backward state transitions (e.g. `RUNNING` → `WAITING_FOR_AUTH`) but the flag overwrite at step 1 already happened. The transaction continues running with corrupted flags. 3. Late flag read at execution time (lines 2273–2277): The scheduler's idle callback reads cached_transaction_flags at dispatch time, not at authorization time. If flags were overwritten between authorization and execution, the backend sees the attacker's flags.","modified":"2026-06-30T18:18:04.671368883Z","published":"2026-04-23T00:00:00Z","related":["USN-8195-1","USN-8195-2","USN-8195-3"],"upstream":["CVE-2026-41651"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-41651"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-41651"},{"type":"REPORT","url":"https://lists.freedesktop.org/archives/packagekit/2026-April/026513.html"},{"type":"REPORT","url":"https://github.com/PackageKit/PackageKit/security/advisories/GHSA-f55j-vvr9-69xv"},{"type":"REPORT","url":"https://github.security.telekom.com/2026/04/pack2theroot-linux-local-privilege-escalation.html"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8195-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8195-2"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8195-3"}],"affected":[{"package":{"name":"packagekit","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/packagekit?arch=source&distro=esm-infra%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1"}]}],"versions":["0.8.17-4ubuntu6~gcc5.3","0.8.17-4ubuntu6~gcc5.4ubuntu1","0.8.17-4ubuntu6~gcc5.4ubuntu1.1","0.8.17-4ubuntu6~gcc5.4ubuntu1.2","0.8.17-4ubuntu6~gcc5.4ubuntu1.3","0.8.17-4ubuntu6~gcc5.4ubuntu1.4","0.8.17-4ubuntu6~gcc5.4ubuntu1.5"],"ecosystem_specific":{"priority_reason":"Local privilege escalation to the root user.","binaries":[{"binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1","binary_name":"gir1.2-packagekitglib-1.0"},{"binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1","binary_name":"gstreamer1.0-packagekit"},{"binary_name":"libpackagekit-glib2-16","binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1"},{"binary_name":"packagekit","binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1"},{"binary_name":"packagekit-backend-aptcc","binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1"},{"binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1","binary_name":"packagekit-backend-smart"},{"binary_name":"packagekit-docs","binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1"},{"binary_name":"packagekit-gtk3-module","binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1"},{"binary_name":"packagekit-tools","binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1"},{"binary_version":"0.8.17-4ubuntu6~gcc5.4ubuntu1.5+esm1","binary_name":"python3-packagekit"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41651.json"}},{"package":{"name":"packagekit","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/packagekit?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.9-1ubuntu2.18.04.6+esm1"}]}],"versions":["1.1.7-1","1.1.9-1","1.1.9-1ubuntu1","1.1.9-1ubuntu2","1.1.9-1ubuntu2.18.04.1","1.1.9-1ubuntu2.18.04.3","1.1.9-1ubuntu2.18.04.4","1.1.9-1ubuntu2.18.04.5","1.1.9-1ubuntu2.18.04.6"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","priority_reason":"Local privilege escalation to the root user.","binaries":[{"binary_name":"gir1.2-packagekitglib-1.0","binary_version":"1.1.9-1ubuntu2.18.04.6+esm1"},{"binary_version":"1.1.9-1ubuntu2.18.04.6+esm1","binary_name":"gstreamer1.0-packagekit"},{"binary_name":"libpackagekit-glib2-18","binary_version":"1.1.9-1ubuntu2.18.04.6+esm1"},{"binary_name":"packagekit","binary_version":"1.1.9-1ubuntu2.18.04.6+esm1"},{"binary_version":"1.1.9-1ubuntu2.18.04.6+esm1","binary_name":"packagekit-command-not-found"},{"binary_version":"1.1.9-1ubuntu2.18.04.6+esm1","binary_name":"packagekit-docs"},{"binary_name":"packagekit-gtk3-module","binary_version":"1.1.9-1ubuntu2.18.04.6+esm1"},{"binary_name":"packagekit-tools","binary_version":"1.1.9-1ubuntu2.18.04.6+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41651.json"}},{"package":{"name":"packagekit","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/packagekit?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.13-2ubuntu1.1+esm1"}]}],"versions":["1.1.12-5ubuntu4","1.1.13-1","1.1.13-2","1.1.13-2build1","1.1.13-2ubuntu1","1.1.13-2ubuntu1.1"],"ecosystem_specific":{"priority_reason":"Local privilege escalation to the root user.","binaries":[{"binary_name":"gir1.2-packagekitglib-1.0","binary_version":"1.1.13-2ubuntu1.1+esm1"},{"binary_version":"1.1.13-2ubuntu1.1+esm1","binary_name":"gstreamer1.0-packagekit"},{"binary_name":"libpackagekit-glib2-18","binary_version":"1.1.13-2ubuntu1.1+esm1"},{"binary_name":"packagekit","binary_version":"1.1.13-2ubuntu1.1+esm1"},{"binary_version":"1.1.13-2ubuntu1.1+esm1","binary_name":"packagekit-command-not-found"},{"binary_name":"packagekit-docs","binary_version":"1.1.13-2ubuntu1.1+esm1"},{"binary_version":"1.1.13-2ubuntu1.1+esm1","binary_name":"packagekit-gtk3-module"},{"binary_name":"packagekit-tools","binary_version":"1.1.13-2ubuntu1.1+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41651.json"}},{"package":{"name":"packagekit","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/packagekit?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.5-2ubuntu3.1"}]}],"versions":["1.2.2-2ubuntu3","1.2.4-1ubuntu1","1.2.4-1ubuntu2","1.2.5-1ubuntu1","1.2.5-2ubuntu1","1.2.5-2ubuntu2","1.2.5-2ubuntu3"],"ecosystem_specific":{"priority_reason":"Local privilege escalation to the root user.","binaries":[{"binary_name":"gir1.2-packagekitglib-1.0","binary_version":"1.2.5-2ubuntu3.1"},{"binary_name":"gstreamer1.0-packagekit","binary_version":"1.2.5-2ubuntu3.1"},{"binary_name":"libpackagekit-glib2-18","binary_version":"1.2.5-2ubuntu3.1"},{"binary_name":"packagekit","binary_version":"1.2.5-2ubuntu3.1"},{"binary_version":"1.2.5-2ubuntu3.1","binary_name":"packagekit-command-not-found"},{"binary_name":"packagekit-docs","binary_version":"1.2.5-2ubuntu3.1"},{"binary_name":"packagekit-gtk3-module","binary_version":"1.2.5-2ubuntu3.1"},{"binary_name":"packagekit-tools","binary_version":"1.2.5-2ubuntu3.1"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41651.json"}},{"package":{"name":"packagekit","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/packagekit?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.8-2ubuntu1.5"}]}],"versions":["1.2.7-1","1.2.8-1","1.2.8-1build1","1.2.8-2","1.2.8-2build2","1.2.8-2build3","1.2.8-2ubuntu1","1.2.8-2ubuntu1.1","1.2.8-2ubuntu1.2","1.2.8-2ubuntu1.4"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-packagekitglib-1.0","binary_version":"1.2.8-2ubuntu1.5"},{"binary_name":"gstreamer1.0-packagekit","binary_version":"1.2.8-2ubuntu1.5"},{"binary_name":"libpackagekit-glib2-18","binary_version":"1.2.8-2ubuntu1.5"},{"binary_name":"packagekit","binary_version":"1.2.8-2ubuntu1.5"},{"binary_name":"packagekit-command-not-found","binary_version":"1.2.8-2ubuntu1.5"},{"binary_version":"1.2.8-2ubuntu1.5","binary_name":"packagekit-docs"},{"binary_version":"1.2.8-2ubuntu1.5","binary_name":"packagekit-gtk3-module"},{"binary_name":"packagekit-tools","binary_version":"1.2.8-2ubuntu1.5"}],"availability":"No subscription required","priority_reason":"Local privilege escalation to the root user."},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41651.json"}},{"package":{"name":"packagekit","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/packagekit?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.1-1ubuntu1.1"}]}],"versions":["1.3.0-3build1","1.3.1-1","1.3.1-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.3.1-1ubuntu1.1","binary_name":"gir1.2-packagekitglib-1.0"},{"binary_version":"1.3.1-1ubuntu1.1","binary_name":"gstreamer1.0-packagekit"},{"binary_name":"libpackagekit-glib2-18","binary_version":"1.3.1-1ubuntu1.1"},{"binary_name":"packagekit","binary_version":"1.3.1-1ubuntu1.1"},{"binary_name":"packagekit-command-not-found","binary_version":"1.3.1-1ubuntu1.1"},{"binary_name":"packagekit-docs","binary_version":"1.3.1-1ubuntu1.1"},{"binary_name":"packagekit-gtk3-module","binary_version":"1.3.1-1ubuntu1.1"},{"binary_version":"1.3.1-1ubuntu1.1","binary_name":"packagekit-tools"}],"availability":"No subscription required","priority_reason":"Local privilege escalation to the root user."},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41651.json"}},{"package":{"name":"packagekit","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/packagekit?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.4-3ubuntu1"}]}],"versions":["1.3.1-1","1.3.2-1","1.3.3-1","1.3.4-1","1.3.4-3"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-packagekitglib-1.0","binary_version":"1.3.4-3ubuntu1"},{"binary_name":"gstreamer1.0-packagekit","binary_version":"1.3.4-3ubuntu1"},{"binary_name":"libpackagekit-glib2-18","binary_version":"1.3.4-3ubuntu1"},{"binary_name":"packagekit","binary_version":"1.3.4-3ubuntu1"},{"binary_name":"packagekit-command-not-found","binary_version":"1.3.4-3ubuntu1"},{"binary_name":"packagekit-docs","binary_version":"1.3.4-3ubuntu1"},{"binary_version":"1.3.4-3ubuntu1","binary_name":"packagekit-gtk3-module"}],"availability":"No subscription required","priority_reason":"Local privilege escalation to the root user."},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-41651.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"},{"type":"Ubuntu","score":"high"}]}