7.5

CVE-2026-27942: naturalintelligence fast-xml-parser Classic Buffer Overflow

CVSS: 7.5v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-27942DEBIAN-CVE-2026-27942CGA-4544-gh72-59wp
Published 26-02-2026Last modified 23-06-2026
Open JSON

Vulnerability summary

CVE-2026-27942 is a high (CVSS 7.5) Classic Buffer Overflow vulnerability in naturalintelligence fast-xml-parser. EPSS estimates a 0.67% chance of exploitation in the next 30 days, higher than 51% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.67%
0%100%
Low · +0.19 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-83FG-7MMW-C32R

Timeline

  1. 26-02-2026
    PublishedVulnerability first disclosed.
  2. 23-06-2026
    Last modifiedVulnerability information updated.

Description

fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.

CVSS metrics

9 scores · 7 sources · 2 versions

EPSS trend

Probability

0.67%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

+0.19 pp

From 0.48% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.67%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard34 products
  • airflow-2All versions (No fix recorded)
  • airflow-core-2All versions (No fix recorded)
  • dbgate< 7.1.2-r1
  • dbgate-fips< 7.1.2-r0
  • jitsucom-jitsu-console< 2.11.0-r16
Wolfi7 products
  • jitsucom-jitsu-console< 2.11.0-r16
  • kubeflow-pipelines-frontend< 2.16.0-r2
  • opensearch-dashboards-3< 3.5.0-r3
  • prism< 5.14.3-r8
  • renovate< 43.48.3-r0
Debian1 product
  • node-webfontAll versions (No fix recorded)
Naturalintelligence1 product
Npm1 product
  • fast-xml-parser≥ 5.0.0, < 5.3.8 | ≥ 4.0.0-beta.0, < 4.5.4
Ubuntu1 product
  • node-webfontAll versions (No fix recorded)

6 vendors · 45 products

References

9 links