ZDF
Sign inSign up

Vulnerabilities

Vulnerability · 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.

Published May 25, 2021 · catalog updated Oct 14, 2026 · The mq_notify function in

Check if you run it

No confirmed exploitation is on record for CVE-2021-33574. EPSS is 3.52%. Act only if a listed version of The mq_notify function in is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (The mq_notify function in).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
3.52%
Remediation
Advisory link
Affected products
cpe fedoraproject/fedora · cpe gnu/glibc · cpe netapp/cloud backup · cpe netapp/e-series santricity os controller · cpe netapp/h300e firmware · cpe netapp/h300s firmware

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe fedoraproject/fedora33
  • cpe fedoraproject/fedora34
  • cpe gnu/glibc2.32
  • cpe gnu/glibc2.33
  • cpe netapp/cloud backupversion unspecified
  • cpe netapp/e-series santricity os controllerversion unspecified
  • cpe netapp/h300e firmwareversion unspecified
  • cpe netapp/h300s firmwareversion unspecified
  • cpe netapp/h500e firmwareversion unspecified
  • cpe netapp/h500s firmwareversion unspecified
  • cpe netapp/h700s firmwareversion unspecified
  • cpe netapp/solidfire baseboard management controller firmwareversion unspecified

How to fix CVE-2021-33574

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2021-33574. EPSS is 3.52%. Act only if a listed version of The mq_notify function in is installed.

Which versions are affected?

Compare what you have installed with 33, 34, 2.32, 2.33. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-416: Use After Free. EPSS 3.52%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 25, 2021 · NIST NVD

    Detected

    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.

  2. Oct 14, 2026 · NIST NVD

    Updated

    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.

Sources

  • CVE.orgVulnerability recordCVE-2021-33574

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-33574

    30-day exploitation probability 3.5%

    first.org
  • NIST NVDVulnerability recordCVE-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 (applicat

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.