Out-of-bounds Read Affecting PelionIoT/mbed-coap package, versions [,5.1.6)


Severity

Recommended
0.0
critical
0
10

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Threat Intelligence

EPSS
1.35% (68th percentile)

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  • Snyk IDSNYK-UNMANAGED-PELIONIOTMBEDCOAP-15323756
  • published20 Feb 2026
  • disclosed18 Jun 2020
  • creditUnknown

Introduced: 18 Jun 2020

CVE-2020-12884  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade PelionIoT/mbed-coap to version 5.1.6 or higher.

Overview

Affected versions of this package are vulnerable to Out-of-bounds Read. A buffer over-read 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 that may occur multiple consecutive times in a single packet. While processing the options, packet_data_pptr is accessed after being incremented by option_len without a prior out-of-bounds memory check. The temp_parsed_uri_query_ptr is validated for a correct range, but the range valid for temp_parsed_uri_query_ptr is derived from the amount of allocated heap memory, not the actual input size. Therefore the check of temp_parsed_uri_query_ptr may be insufficient for safe access to the area pointed to by packet_data_pptr. As a result, access to a memory area outside of the intended boundary of the packet buffer is made.

CVSS Base Scores

version 3.1