How severe is CVE-2021-44732?

CVE-2021-44732 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-44732 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-44732?

CVE-2021-44732 primarily affects Arm Mbed Tls. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-44732?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-44732 published?

CVE-2021-44732 was published on 2021-12-20 and last updated on 2026-06-17.

CVE-2021-44732

CVE-2021-44732 is a critical-severity vulnerability in Arm Mbed Tls with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-415.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-415
Affected product: Arm Mbed Tls
Published: 2021-12-20
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-44732?: 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.
How severe is CVE-2021-44732?: CVE-2021-44732 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-44732 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-44732?: CVE-2021-44732 primarily affects Arm Mbed Tls. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-44732?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-44732 published?: CVE-2021-44732 was published on 2021-12-20 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*
cpe:2.3:a:trustedfirmware:mbed_tls:3.0.0:-:*:*:*:*:*:*
cpe:2.3:a:trustedfirmware:mbed_tls:3.0.0:preview1:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

More vulnerabilities in Arm Mbed Tls

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CVE-2018-0488 — Critical (CVSS 9.8): ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0, when the truncated HMAC extension and CBC are used, allows…
CVE-2018-0487 — Critical (CVSS 9.8): ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0 allows remote attackers to execute arbitrary code or cause…
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All CVEs affecting Arm Mbed Tls →

Other CWE-415 (Double Free) vulnerabilities

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CVE-2026-8925 — Critical (CVSS 9.8): The curl logic that works with SASL authentication could end up cleaning up the GSASL context *twice* without clearing…
CVE-2020-37239 — Critical (CVSS 9.8): libbabl 0.1.62 contains a broken double free detection vulnerability that allows attackers to bypass memory safety…
CVE-2026-43011 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix potential double free of skb When…
CVE-2026-31609 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid double-free in…
CVE-2026-31608 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: server: avoid double-free in…

Browse all CWE-415 (Double Free) vulnerabilities →