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-2020-29573

CVE-2020-29573HIGH

n/a n/a — sysdeps/i386/ldbl2mpn.c in the GNU C Library (aka glibc or libc6) before 2.23 on x86 targets has a stack-based buffer overflow if the inp…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0272   85.8     —

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

TIMELINE
  Dec 5   Reserved by mitre
  Dec 5   Published (CNA: mitre)
  Oct 14  ENRICHED — CVE-2020-29573. Received CVSS 7.5 and CPE data from NVD.

CWE-787 · CNA: mitre · CVSS v3.1 · 5 references · NVD status: Modified

Description

sysdeps/i386/ldbl2mpn.c in the GNU C Library (aka glibc or libc6) before 2.23 on x86 targets has a stack-based buffer overflow if the input to any of the printf family of functions is an 80-bit long double with a non-canonical bit pattern, as seen when passing a \x00\x04\x00\x00\x00\x00\x00\x00\x00\x04 value to sprintf. NOTE: the issue does not affect glibc by default in 2016 or later (i.e., 2.23 or later) because of commits made in 2015 for inlining of C99 math functions through use of GCC built-ins. In other words, the reference to 2.23 is intentional despite the mention of "Fixed for glibc 2.33" in the 26649 reference.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
December 5, 2020	Reserved	Reserved by mitre
December 5, 2020	Published	Published (CNA: mitre)
October 14, 2026	ENRICHED	ENRICHED — CVE-2020-29573. Received CVSS 7.5 and CPE data from NVD.

Affected

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

Weaknesses

CWE-787

References (5)

https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://security.gentoo.org/glsa/202101-20 [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20210122-0004/ [Third Party Advisory]
https://sourceware.org/bugzilla/show_bug.cgi?id=26649 [Issue Tracking, Patch, Third Party Advisory]
https://sourceware.org/pipermail/libc-alpha/2020-September/117779.html [Patch, Third Party Advisory]

Authoritative record: CVE-2020-29573 at cve.org

Weaknesses: CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-29573 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.