Amazon Linux 2 : PackageKit, --advisory ALAS2-2026-3282 (ALAS-2026-3282)

high Nessus Plugin ID 314573

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of PackageKit installed on the remote host is prior to 1.1.5-2. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3282 advisory.

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. (CVE-2026-41651)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update PackageKit' or or 'yum update --advisory ALAS2-2026-3282' to update your system.

Plugin Details

Severity: High

ID: 314573

File Name: al2_ALAS-2026-3282.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 5/14/2026

Updated: 5/14/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 10.0

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-41651

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:packagekit-gtk3-module, p-cpe:/a:amazon:linux:packagekit, p-cpe:/a:amazon:linux:packagekit-gstreamer-plugin, p-cpe:/a:amazon:linux:packagekit-glib-devel, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:packagekit-yum-plugin, p-cpe:/a:amazon:linux:packagekit-cron, p-cpe:/a:amazon:linux:packagekit-glib, p-cpe:/a:amazon:linux:packagekit-debuginfo, p-cpe:/a:amazon:linux:packagekit-command-not-found, p-cpe:/a:amazon:linux:packagekit-yum

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/14/2026

Vulnerability Publication Date: 4/22/2026

Reference Information

CVE: CVE-2026-41651

Detections

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