Summary
Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2026-41651: 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->cached_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->cached_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.
Fixed packages 10
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2 | PackageKit | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-command-not-found | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-cron | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-debuginfo | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-glib | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-glib-devel | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-gstreamer-plugin | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-gtk3-module | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-yum | 0:1.1.5-2.amzn2.0.4 |
| Amazon Linux · 2 | PackageKit-yum-plugin | 0:1.1.5-2.amzn2.0.4 |
Vulnerabilities 1
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High 8.8CVE-2026-41651 Public exploit
PackageKit vulnerable to TOCTOU Race on Transaction Flags leads to arbitrary package installation as root
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) rac…
References
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web
https://alas.aws.amazon.com/cve/html/CVE-2026-41651.html