Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-46143

CVE-2021-46143HIGH

n/a n/a — In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   N   R  U  H  H  H    7.8   .0422   90.9     —

AFFECTED
  Product  Versions  Fixed
  n/a      n/a –     —

TIMELINE
  Jan 6   Reserved by mitre
  Jan 6   Published (CNA: mitre)
  Oct 14  EXPLOIT PUBLISHED — CVE-2021-46143. Public exploit reference added.
  Oct 14  RESCORED — CVE-2021-46143. CVSS 8.1 → 7.8 (NVD).

CWE-190 · CNA: mitre · CVSS v3.1 · 10 references · NVD status: Modified

Description

In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
January 6, 2022	Reserved	Reserved by mitre
January 6, 2022	Published	Published (CNA: mitre)
October 14, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2021-46143. Public exploit reference added.
October 14, 2026	RESCORED	RESCORED — CVE-2021-46143. CVSS 8.1 → 7.8 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	n/a	—	n/a	—

Weaknesses

CWE-190

References (10)

http://www.openwall.com/lists/oss-security/2022/01/17/3 [Mailing List, Patch, Third Party Advisory]
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://cert-portal.siemens.com/productcert/html/ssa-484086.html
https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf [Patch, Third Party Advisory]
https://github.com/libexpat/libexpat/issues/532 [Exploit, Issue Tracking, Patch, Third Party Advisory]
https://github.com/libexpat/libexpat/pull/538 [Patch, Third Party Advisory]
https://security.gentoo.org/glsa/202209-24 [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20220121-0006/ [Third Party Advisory]
https://www.debian.org/security/2022/dsa-5073 [Third Party Advisory]
https://www.tenable.com/security/tns-2022-05 [Third Party Advisory]

Authoritative record: CVE-2021-46143 at cve.org

Weaknesses: CWE-190

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-46143 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.