How severe is CVE-2020-12885?

CVE-2020-12885 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-2020-12885 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-12885?

CVE-2020-12885 affects Arm Mbed Os. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-12885?

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-2020-12885 published?

CVE-2020-12885 was published on 2020-06-18 and last updated on 2026-06-17.

CVE-2020-12885

CVE-2020-12885 is a high-severity vulnerability in Arm Mbed Os 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-835.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-835
Affected product: Arm Mbed Os
Published: 2020-06-18
Last modified: 2026-06-17

Description

An infinite loop was discovered in the CoAP library in Arm Mbed OS 5.15.3. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse_multiple_options() parses CoAP options in a while loop. This loop's exit condition is computed using the previously allocated heap memory required for storing the result of parsing multiple options. If the input heap memory calculation results in zero bytes, the loop exit condition is never met and the loop is not terminated. As a result, the packet parsing function never exits, leading to resource consumption.

Frequently asked questions

What is CVE-2020-12885?: An infinite loop was discovered in the CoAP library in Arm Mbed OS 5.15.3. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse_multiple_options() parses CoAP options in a while loop. This loop's exit condition is computed using the previously allocated heap memory required for storing the result of parsing multiple options. If the input heap memory calculation results in zero bytes, the loop exit condition is never met and the loop is not terminated. As a result, the packet parsing function never exits, leading to resource consumption.
How severe is CVE-2020-12885?: CVE-2020-12885 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-2020-12885 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-12885?: CVE-2020-12885 affects Arm Mbed Os. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-12885?: 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-2020-12885 published?: CVE-2020-12885 was published on 2020-06-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:arm:mbed_os:5.15.3:*:*:*:*:*:*:*

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