Chainguard: synapse: security update to 1.164.1-r2

high Tenable Self-Hosted Container Security Plugin ID 478033

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to
26.10.0rc1, the twisted.words.xish.domish ExpatElementStream parser allows an unauthenticated remote peer
to keep a container element open while continuously adding child elements. The parser retains the
unfinished stanza as an in-memory tree without a byte or element-count limit, and XMPP pre-authentication
stream parsing exposes this behavior before credentials are accepted. A single connection can therefore
exhaust server memory and terminate the process. This issue is fixed in version 26.10.0rc1.
(CVE-2026-115775)

Solution

Update the synapse library and its related packages to version 1.164.1-r2 or later.

Plugin Details

Severity: High

ID: 478033

Version: Revision 1.1

Type: Local

Family: Chainguard Local Security Checks

Published: 10/31/2026

Updated: 10/31/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.73

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2026-115775

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 10/23/2026

Reference Information

CVE: CVE-2026-115775

Detections

Analytics