7.5

CVE-2021-38604: fedoraproject fedora NULL Pointer Dereference

CVSS: 7.5v3.1HighModified
AliasesMGASA-2021-0404UBUNTU-CVE-2021-38604
Published 12-08-2021Last modified 14-10-2026
Open JSON

Vulnerability summary

CVE-2021-38604 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in fedoraproject fedora. EPSS estimates a 3.72% chance of exploitation in the next 30 days, higher than 89.6% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
41/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
3.72%
0%100%
Low · +0.68 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Timeline

  1. 12-08-2021
    PublishedVulnerability first disclosed.
  2. 14-10-2026
    Last modifiedVulnerability information updated.

Description

In librt in the GNU C Library (aka glibc) through 2.34, sysdeps/unix/sysv/linux/mq_notify.c mishandles certain NOTIFY_REMOVED data, leading to a NULL pointer dereference. NOTE: this vulnerability was introduced as a side effect of the CVE-2021-33574 fix.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

3.72%

Chance of exploitation in the next 30 days

Percentile

90%

Versus all other CVEs

30-day change

+0.68 pp

From 3.04% on 19-09-2026

19-09-202619-10-2026
EPSS score
3.72%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (blog.tuxcare.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Oracle6 products
Fedoraproject1 product
Gnu1 product
Mageia1 product
  • glibc< 2.32-18.mga8
Ubuntu1 product
  • glibc< 2.34-0ubuntu3

5 vendors · 10 products

References

15 links
Show all 15 references