Detections
Analytics

Chainguard: synapse: security update to 1.164.1-r2

medium Tenable Cloud Security Plugin ID 478036

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, twisted.mail.imap4.IMAP4Server reaches twisted.mail.imap4.parseNestedParens with a negative
 literal size in an authenticated SEARCH command after the client enters the selected mailbox state. The
 negative size moves the parser cursor below zero, and Python's negative indexing prevents the synchronous
 scanning loop from terminating. The loop freezes the single-threaded reactor, stopping other IMAP
 connections and any SMTP or POP3 services hosted in the same process until restart. This issue is fixed in
 version 26.10.0rc1. (CVE-2026-115774)

Solution

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

Plugin Details

Severity: Medium

ID: 478036

Version: Revision 1.1

Type: Local

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: 6.1

Temporal Score: 4.5

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

CVSS Score Source: CVE-2026-115774

CVSS v3

Risk Factor: Medium

Base Score: 4.9

Temporal Score: 4.3

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

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

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 10/23/2026

Reference Information

CVE: CVE-2026-115774