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 &#65; 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.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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 processeven when developers     have configured strict limits. This issue has been fixed in version 5.5.6. (CVE-2026-33036)

Note that Nessus relies on the presence of the package as reported by the vendor.

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 &#65; 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)

ID	Name	Product	Family	Severity
303270	Linux Distros Unpatched Vulnerability : CVE-2026-33036	Nessus	Misc.	high
438905	SCA: security update for fast-xml-parser (GHSA-8gc5-j5rx-235r)	Tenable Cloud Security	SCA Checks	high
438905	SCA: security update for fast-xml-parser (GHSA-8gc5-j5rx-235r)	Tenable Self-Hosted Container Security	SCA Checks	high

Detections

Analytics

CVE-2026-33036

high

Tenable Plugins

high

high

high