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Echo: fast-xml-parser: security update to 4.5.5

medium Tenable Self-Hosted Container Security Plugin ID 465267

Description

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

 - fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks.
 From version 4.0.0-beta.3 to before version 5.5.7, the DocTypeReader in fast-xml-parser uses JavaScript
 truthy checks to evaluate maxEntityCount and maxEntitySize configuration limits. When a developer
 explicitly sets either limit to 0 — intending to disallow all entities or restrict entity size to zero
 bytes — the falsy nature of 0 in JavaScript causes the guard conditions to short-circuit, completely
 bypassing the limits. An attacker who can supply XML input to such an application can trigger unbounded
 entity expansion, leading to memory exhaustion and denial of service. This issue has been patched in
 version 5.5.7. (CVE-2026-33349)

Solution

Update the fast-xml-parser library and its related packages to version 4.5.5 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-33349

Plugin Details

Severity: Medium

ID: 465267

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/3/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 94.39

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4.2

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

CVSS Score Source: CVE-2026-33349

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.3

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

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

Vulnerability Information

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/28/2026

Vulnerability Publication Date: 3/19/2026

Reference Information

CVE: CVE-2026-33349