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Fencer Vulns
critical 9.8

CVE-2021-44732 json

Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an...

published 2021-12-20 4 y ago modified 2026-07-23 3 mo ago also EUVD-2021-31547 , JLSEC-2025-214

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.8%
EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an mbedtls_ssl_set_session() failure.

Patch / fix

  • julia MbedTLS_jll 2.28.0+0
  • arm mbed_tls 2.16.12, 2.28.0
  • mbedtls Debian 14, Debian 13, Debian 12 2.28.0-0.3

debian advisories DEBIAN-CVE-2021-44732

  • mbedtls Ubuntu Pro 18.04 LTS 2.8.0-1ubuntu0.1~esm1
  • mbedtls Ubuntu Pro 20.04 LTS 2.16.4-1ubuntu2+esm1

ubuntu advisories UBUNTU-CVE-2021-44732

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • mbedtls Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 2.16.12-r0
  • mbedtls2 Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 2.16.12-r0
  • mbedtls3 Alpine 3.24 2.16.12-r0

alpine advisories ALPINE-CVE-2021-44732

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-44732 updated cvss 9.8

mbedtls: potential double-free after an out of memory error

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.77% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • tls.mbed.org https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-12 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
OSV 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia MbedTLS_jll
<2.28.0+0
2.28.0+0

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.