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Vulnerability record · CVE-2021-33574 · published 25 May 2021

CVE-2021-33574: Gnu glibc use after free vulnerability

Gnu · Glibc

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.

9.8 CVSS 3.1 Critical EPSS 2.9% · top 13.7% CWE-416 · Use after free
9.8CVSS 3.1 base score, v2 7.5
2.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
13Affected product versions listed by NVD
14References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

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

Affected products

13 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJYYIMDDYOHTP2PORLABTOH
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RBUUWUGXVILQXVWEOU7N42I
https://security.gentoo.org/glsa/202107-07 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210629-0005/ Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896 ExploitIssue TrackingThird Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896#c1 Issue Tracking
https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJYYIMDDYOHTP2PORLABTOH
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RBUUWUGXVILQXVWEOU7N42I
https://security.gentoo.org/glsa/202107-07 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210629-0005/ Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896 ExploitIssue TrackingThird Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=27896#c1 Issue Tracking

Track CVE-2021-33574 inside VULONE

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Source: NIST National Vulnerability Database (record CVE-2021-33574), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.