Sentry Python Library 21.12.x < 26.4.1 Improper Authentication (CVE-2026-42354)

critical Nessus Plugin ID 313233

Synopsis

A Python library installed on the remote host is affected by an improper authentication vulnerability.

Description

The version of Sentry installed on the remote host is 21.12.0 or later but prior to 26.4.1. It is, therefore, affected by a vulnerability:

- A critical vulnerability exists in the SAML SSO implementation of Sentry. The vulnerability allows an attacker to take over any user account by using a malicious SAML Identity Provider and another organization on the same Sentry instance. The victim email address must be known in order to exploit this vulnerability. Self-hosted users are only vulnerable if they have more than one organization configured and a malicious user has existing access and permissions to modify SSO settings for another organization. (CVE-2026-42354)

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

Solution

Upgrade to Sentry version 26.4.1 or later.

Plugin Details

Severity: Critical

ID: 313233

File Name: sentry_CVE-2026-42354.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 5/8/2026

Updated: 5/8/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: High

Base Score: 9.4

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

CVSS Score Source: CVE-2026-42354

CVSS v3

Risk Factor: Critical

Base Score: 9.1

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

Vulnerability Information

CPE: cpe:/a:sentry:sentry

Patch Publication Date: 4/30/2026

Vulnerability Publication Date: 4/30/2026

Reference Information

CVE: CVE-2026-42354

IAVA: 2026-A-0420

Detections

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