CVE-2026-33036

HIGHPre-NVD 7.57.5
EchelonGraph scoreLOW confidence

This high-severity CVE scores 7.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
Trending — 4 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

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.

CVSS v3
7.5
EG Score
7.5(low)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
44%
KEV
Not listed

Published

March 20, 2026

Last Modified

June 17, 2026

References (3)

Vendor Advisories for CVE-2026-33036(11)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(11)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatodf4/rook-ceph-rhel9-operator:17836775332026-07-20redhat
redhatodf4/rook-ceph-rhel9-operator:17836853752026-07-20redhat
redhatodf4/rook-ceph-rhel9-operator:17836692192026-07-16redhat
redhatodf4/rook-ceph-rhel9-operator:17780460792026-05-14redhat
redhatodf4/rook-ceph-rhel9-operator:17780778392026-05-14redhat
redhatodf4/rook-ceph-rhel9-operator:17780504822026-05-14redhat
redhatodf4/rook-ceph-rhel9-operator:17760797742026-04-30redhat
redhatodf4/rook-ceph-rhel9-operator:17758232072026-04-30redhat
redhatrhdh/rhdh-hub-rhel9:17767842862026-04-22redhat
redhatadvanced-cluster-security/rhacs-main-rhel8:17755941192026-04-08redhat
redhatadvanced-cluster-security/rhacs-main-rhel8:17755942842026-04-08redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
fast-xml-parser—5.5.6—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 7× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-01 04:16 UTCEPSS rescore
  2. 2026-07-30 16:28 UTCEPSS rescore
  3. 2026-07-30 01:30 UTCEPSS rescore
  4. 2026-07-27 14:13 UTCEPSS rescore
  5. 2026-07-27 12:51 UTCEG score recompute
  6. 2026-07-27 12:51 UTCVendor advisory
  7. 2026-07-27 12:50 UTCOSV refresh

Frequently asked(5)

What is CVE-2026-33036?
CVE-2026-33036 is a high vulnerability published on March 20, 2026. 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.,…
When was CVE-2026-33036 disclosed?
CVE-2026-33036 was first published in the National Vulnerability Database on March 20, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33036 actively exploited?
CVE-2026-33036 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 55.8% of all scored CVEs.
What is the CVSS score of CVE-2026-33036?
CVE-2026-33036 has a CVSS v3 base score of 7.5 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-33036?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33036, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-33036

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