CVE-2021-33574

The mq_notify function in the GNU C Library (aka glibc) versions 2.32 and 2.33 has a use-after-free. It may use the notification thread attributes object (passed through its struct sigevent parameter) after it has been freed by the caller, leading to a denial of service (application crash) or possibly unspecified other impact.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

3.5% chance of exploitation in the next 30 days; higher than 89% of CVEs (scores of 2026-10-25)

CWE

CWE-416

Published

2021-05-25

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• debian:debian_linux
• fedoraproject:fedora
• gnu:glibc
• netapp:cloud_backup
• netapp:e-series_santricity_os_controller
• netapp:h300e_firmware
• netapp:h300s_firmware
• netapp:h410s_firmware
• netapp:h500e_firmware
• netapp:h500s_firmware
• netapp:h700e_firmware
• netapp:h700s_firmware
• netapp:solidfire_baseboard_management_controller_firmware

References

• https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJYYIMDDYOHTP2PORLABTOHYQYYREZDD/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RBUUWUGXVILQXVWEOU7N42ICHPJNAEUP/
• https://security.gentoo.org/glsa/202107-07
• https://security.netapp.com/advisory/ntap-20210629-0005/

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