CVE-2020-29573

medium
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
5.5

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.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2020-29573

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2020-29573.html

OS impact

OSVersionStatusFixed in
arch archaffected
suse slesaffected
debian debianbookwormfixed2.23-1
debian debianbullseyefixed2.23-1
debian debianforkyfixed2.23-1
debian debiansidfixed2.23-1
debian debiantrixiefixed2.23-1

References

Verify integrity in audit chain (admin only). AS-IS.