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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | glibc | 2.23-1 | — |
| Debian 13 | glibc | 2.23-1 | — |
| Debian 12 | glibc | 2.23-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | eglibc | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | nscd +7 | 2.17-322.el7_9 | RHSA-2021:0348 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7.7 EUS | nscd +7 | 2.17-292.el7_7.2 | RHSA-2021:2998 |
| RHEL 7.6 TUS | nscd +7 | 2.17-260.el7_6.9 | RHSA-2021:3315 |
| RHEL 7.6 E4S | nscd +7 | 2.17-260.el7_6.9 | RHSA-2021:3315 |
| RHEL 7.6 AUS | nscd +7 | 2.17-260.el7_6.9 | RHSA-2021:3315 |
| RHEL 7.4 TUS | nscd +7 | 2.17-196.el7_4.4 | RHSA-2021:2813 |
| RHEL 7.4 E4S | nscd +7 | 2.17-196.el7_4.4 | RHSA-2021:2813 |
| RHEL 7.4 AUS | nscd +7 | 2.17-196.el7_4.4 | RHSA-2021:2813 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SLES 15 SP1 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SLES 15 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SLES 12 SP5 | glibc | 2.22-114.8.3 | SUSE-SU-2021:1165-1 |
| SLES 12 SP4 | glibc | 2.22-114.8.3 | SUSE-SU-2021:1165-1 |
Show 15 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | glibc | 2.22-126.1 | SUSE-SU-2022:2886-1 |
| SLES 12 SP2 | glibc | 2.22-126.1 | SUSE-SU-2022:2886-1 |
| SLES 11 SP4 | glibc | 2.11.3-17.110.43.1 | SUSE-SU-2024:0759-1 |
| SLES for SAP 15 SP1 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SLES for SAP 15 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SLES for SAP 12 SP5 | glibc | 2.22-114.8.3 | SUSE-SU-2021:1165-1 |
| SLES for SAP 12 SP4 | glibc | 2.22-114.8.3 | SUSE-SU-2021:1165-1 |
| SLE HPC 15 SP1 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SLE HPC 15 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SUSE OpenStack Cloud Crowbar 9 | glibc | 2.22-114.8.3 | SUSE-SU-2021:1165-1 |
| SUSE OpenStack Cloud 9 | glibc | 2.22-114.8.3 | SUSE-SU-2021:1165-1 |
| SUSE Manager Server 4.0 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SUSE Manager Retail Branch Server 4.0 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SUSE Manager Proxy 4.0 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
| SUSE Enterprise Storage 6 | glibc | 2.26-13.56.1 | SUSE-SU-2021:0653-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | glibc | 2.34-1.2 | openSUSE-SU-2024:10792-1 |
| openSUSE Leap 15.2 | glibc +1 | 2.26-lp152.26.6.1 | openSUSE-SU-2021:0358-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | nscd +6 | 2.17-322.0.2.el7_9 | ELSA-2021-0348 |
Advisories 14
- RHSA-2021:3315 Red Hat Security Advisory: glibc security and bug fix update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2021:2998 Red Hat Security Advisory: glibc security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2021:2813 Red Hat Security Advisory: glibc security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2021:0348 Red Hat Security Advisory: glibc security and bug fix update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- SSA-398330 SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5 Siemens ProductCERT · Oct 13, 2026
- SUSE-SU-2024:0759-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10792-1 glibc-2.34-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1165-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:0653-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0358-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:2886-1 Security update for glibc SUSE / openSUSE Security Updates · Feb 4, 2026
- ICSA-23-348-10 Siemens SIMATIC S7-1500 CISA ICS & IT advisories · Aug 12, 2025
- WID-SEC-2022-1169 GNU libc: Mehrere Schwachstellen BSI CERT-Bund (WID) · Mar 5, 2024
- ELSA-2021-0348 Moderate: glibc security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 5, 2021