Reusing a Nonce Affecting kernel-livepatch-6.18.56-125.164 package, versions <1:1.0-0.amzn2023


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.13% (3rd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-AMZN2023-KERNELLIVEPATCH61856125164-21804859
  • published29 Oct 2026
  • disclosed18 Oct 2026

Introduced: 18 Oct 2026

NewCVE-2026-98805  (opens in a new tab)
CWE-323  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-livepatch-6.18.56-125.164 to version 1:1.0-0.amzn2023 or higher.
This issue was patched in ALAS2023-2026-3251.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-livepatch-6.18.56-125.164 package and not the kernel-livepatch-6.18.56-125.164 package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

tipc: prevent GCM nonce reuse on peer key changes

TIPC can encrypt traffic between nodes using a different transmit key for each node. In this mode, the AES-GCM nonce for a packet sent to a known peer consists of a 32-bit prefix (a per-key salt XOR the peer's address) followed by a 64-bit counter. That counter is stored in the peer's RX crypto object. When the peer reports a change in which key it uses to receive packets, TIPC resets this counter. The sender can still be using the same TX key and salt, so subsequent packets reuse earlier nonces. This nonce reuse breaks confidentiality and exposes GCM's authentication key. This makes forgeries trivial: an attacker can exploit CTR malleability to alter captured ciphertexts and use the recovered authentication key to compute a valid tag for the modified ciphertext, under the same key and nonce.

Use the TX key's existing aead->seqno counter instead. All encryptions using that key object share the same atomic counter, so concurrent encryptions get distinct nonce counter values. The counter survives key activation and peer reconnection, and peer key-status reports cannot reset it. This prevents those transitions from causing nonce reuse while the same TX key remains installed.

The nonce format is unchanged, and receivers do not require consecutive counter values, so sharing the counter across peers remains compatible with existing receivers. A pre-existing check still invokes key revocation in the unlikely event that the counter wraps to zero.

CVSS Base Scores

version 3.1