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No exploitation reportedFix available

CVE-2020-29573

No exploitation reported by the sources we read.

  • Published2020-12-06
  • Fixed in2.23
  • WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2020-12-0600:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-29573?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-29573?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Gnu glibc
BranchAffectedFixed in
2.23< 2.232.23
Netapp cloud backup
BranchAffectedFixed in
—all versionsno fix published
Netapp solidfire baseboard management controller
BranchAffectedFixed in
—all versionsno fix published

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Gnu glibc to 2.23

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • NVDweakness (CWE)CWE-787read 2026-10-23
  • FIRST EPSSEPSS score2.7 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2020-12-06
Last Modified
2026-10-14
NVD status
Modified

Frequently asked questions

What is CVE-2020-29573?

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.

Is CVE-2020-29573 actively exploited?

Active exploitation of CVE-2020-29573 has not been confirmed. Its EPSS score was 2.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-29573?

CVE-2020-29573 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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