Detections
Analytics

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

high Tenable Cloud Security Plugin ID 463322

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.
 Versions 4.0.0-beta.3 through 5.5.5 contain a bypass vulnerability where numeric character references
 (&#NNN;, &#xHH;) and standard XML entities completely evade the entity expansion limits (e.g.,
 maxTotalExpansions, maxExpandedLength) added to fix CVE-2026-26278, enabling XML entity expansion Denial
 of Service. The root cause is that replaceEntitiesValue() in OrderedObjParser.js only enforces expansion
 counting on DOCTYPE-defined entities while the lastEntities loop handling numeric/standard entities
 performs no counting at all. An attacker supplying 1M numeric entity references like A can force
 ~147MB of memory allocation and heavy CPU usage, potentially crashing the process—even when developers
 have configured strict limits. This issue has been fixed in version 5.5.6. (CVE-2026-33036)

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-2026-33036

Plugin Details

Severity: High

ID: 463322

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: 93.82

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

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

CVSS Score Source: CVE-2026-33036

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

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:P/RL:O/RC:C

Vulnerability Information

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/28/2026

Vulnerability Publication Date: 3/17/2026

Reference Information

CVE: CVE-2026-33036