Unity Linux 20.1020e / 20.1050e / 20.1060e / 20.1070e Security Update: kernel (UTSA-2026-142511)

critical Nessus Plugin ID 370668

Synopsis

The Unity Linux host is missing one or more security updates.

Description

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-142511 advisory.

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

sctp: keep chunk->transport in step with the list it is queued on

__sctp_outq_flush_rtx() moves a gap-acked chunk onto another transport's transmitted list without updating chunk->transport:

if (chunk->tsn_gap_acked) { list_move_tail(&chunk->transmitted_list, &transport->transmitted);
continue;
}

The chunk then sits on a live transport's list while chunk->transport still names a different one. If that transport is removed - sctp_assoc_rm_peer() from an ASCONF Delete-IP - sctp_transport_free() RCU-frees it and the chunk is left with a dangling pointer. sctp_assoc_rm_peer() scrubs peer->transmitted and asoc->outqueue.out_chunk_list, but the chunk is on neither.

The pointer is not followed while tsn_gap_acked is set. A SACK that reneges on the TSN clears the flag, and the next SACK reaches

tchunk->transport->flight_size -= sctp_data_size(tchunk);

inside the freed transport. KASAN reports a slab-use-after-free read in sctp_check_transmitted(), freed from sctp_assoc_rm_peer(). Both the removal and the SACKs come from the association peer.

Set chunk->transport at the move. The ordinary resend path needs nothing:
it reaches its list_move_tail() only after sctp_packet_append_chunk() returned SCTP_XMIT_OK, and __sctp_packet_append_chunk() has rebound the chunk by then.

Discovered by XBOW, triaged by Baul Lee <[email protected]>

Tenable has extracted the preceding description block directly from the Unity Linux 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

Update the affected kernel package.

Plugin Details

Severity: Critical

ID: 370668

File Name: unity_linux_UTSA-2026-142511.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 10/22/2026

Updated: 10/22/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.39

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-74588

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

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

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 10/22/2026

Vulnerability Publication Date: 8/22/2026

Reference Information

CVE: CVE-2026-74588

Detections

Analytics