How severe is CVE-2020-36475?

CVE-2020-36475 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-36475 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-36475?

CVE-2020-36475 primarily affects Arm Mbed Tls. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-36475?

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

When was CVE-2020-36475 published?

CVE-2020-36475 was published on 2021-08-23 and last updated on 2026-06-17.

CVE-2020-36475

CVE-2020-36475 is a high-severity vulnerability in Arm Mbed Tls with a CVSS 3.x base score of 7.5. 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-131.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-131
Affected product: Arm Mbed Tls
Published: 2021-08-23
Last modified: 2026-06-17

Description

An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters could lead to denial of service when generating Diffie-Hellman key pairs.

Frequently asked questions

What is CVE-2020-36475?: An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters could lead to denial of service when generating Diffie-Hellman key pairs.
How severe is CVE-2020-36475?: CVE-2020-36475 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-36475 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-36475?: CVE-2020-36475 primarily affects Arm Mbed Tls. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-36475?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-36475 published?: CVE-2020-36475 was published on 2021-08-23 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:logo\!_cmr2020_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:logo\!_cmr2040_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_rtu3031c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_rtu3041c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_rtu3030c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_rtu3000c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

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