CVE-2020-12886

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 1.4% (71st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3

Also known asEUVD-2020-5167 (ENISA EUVD) · GHSA-8v45-9mw2-ffmm (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.4%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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() parses the CoAP packet header starting from the message token. The length of the token in the received message is provided in the first byte parsed by the sn_coap_parser_options_parse() function. The length encoded in the message is not validated against the actual input buffer length before accessing the token. As a result, memory access outside of the intended boundary of the buffer may occur.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
41
EG Risk 41/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation1.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
1.4%
EPSS %ILE
71st
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
1.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

June 18, 2020

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated Jul 20, 2026
Patch available. Sources: github_pr.
Web page

Out of range memory access in MbedOS CoAP library parser - token length not validated · Issue #12948 · ARMmbed/mbed-os · GitHub

https://github.com/ARMmbed/mbed-os/issues/12948
GitHub pull request Patch Available

Bugfix/coap parser mem access bugs

Patch available: ARMmbed/mbed-coap v5.1.8 (PR #116 merged 2020-06-22)

https://github.com/ARMmbed/mbed-coap/pull/116

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 14× in last 7d / 60× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 262 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 162 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:38 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  2. 2026-11-13 03:15 UTCEchelonGraph re-scored
  3. 2026-11-13 03:15 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  4. 2026-11-12 16:29 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  5. 2026-11-12 04:27 UTCEchelonGraph re-scored
  6. 2026-11-12 04:27 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  7. 2026-11-11 16:30 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  8. 2026-11-11 05:37 UTCEchelonGraph re-scored
  9. 2026-11-11 05:37 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  10. 2026-11-10 16:34 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  11. 2026-11-10 06:49 UTCEchelonGraph re-scored
  12. 2026-11-10 06:49 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  13. 2026-11-09 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  14. 2026-11-09 08:01 UTCEchelonGraph re-scored
  15. 2026-11-09 08:01 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  16. 2026-11-08 16:31 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  17. 2026-11-08 09:13 UTCEchelonGraph re-scored
  18. 2026-11-08 09:13 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  19. 2026-11-07 16:32 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  20. 2026-11-07 10:25 UTCEchelonGraph re-scored
  21. 2026-11-07 10:25 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  22. 2026-11-06 16:29 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  23. 2026-11-06 11:37 UTCEchelonGraph re-scored
  24. 2026-11-06 11:37 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  25. 2026-11-05 16:29 UTCEPSS rescoreEPSS 1.4% · 71st percentile
Show 75 more
  1. 2026-11-05 12:50 UTCEchelonGraph re-scored
  2. 2026-11-05 12:50 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  3. 2026-11-04 16:29 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  4. 2026-11-04 14:02 UTCEchelonGraph re-scored
  5. 2026-11-04 14:02 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  6. 2026-11-03 16:36 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  7. 2026-11-03 15:14 UTCEchelonGraph re-scored
  8. 2026-11-03 15:14 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  9. 2026-11-02 16:36 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  10. 2026-11-02 16:26 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  11. 2026-11-01 17:26 UTCEchelonGraph re-scored
  12. 2026-11-01 17:26 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm · GitHub severity MODERATE
  13. 2026-10-31 18:38 UTCEchelonGraph re-scored
  14. 2026-10-31 18:38 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  15. 2026-10-31 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  16. 2026-10-30 19:49 UTCEchelonGraph re-scored
  17. 2026-10-30 19:49 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  18. 2026-10-30 16:29 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  19. 2026-10-29 21:00 UTCEchelonGraph re-scored
  20. 2026-10-29 21:00 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  21. 2026-10-29 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  22. 2026-10-28 22:13 UTCEchelonGraph re-scored
  23. 2026-10-28 22:13 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  24. 2026-10-28 16:27 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  25. 2026-10-27 23:24 UTCEchelonGraph re-scored
  26. 2026-10-27 23:23 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  27. 2026-10-27 16:27 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  28. 2026-10-27 00:36 UTCEchelonGraph re-scored
  29. 2026-10-27 00:35 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  30. 2026-10-26 16:27 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  31. 2026-10-25 22:09 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  32. 2026-10-25 18:51 UTCEchelonGraph re-scored
  33. 2026-10-25 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  34. 2026-10-24 23:15 UTCEchelonGraph re-scored
  35. 2026-10-24 23:15 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  36. 2026-10-24 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  37. 2026-10-24 00:28 UTCEchelonGraph re-scored
  38. 2026-10-24 00:28 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  39. 2026-10-23 16:27 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  40. 2026-10-23 01:36 UTCEchelonGraph re-scored
  41. 2026-10-23 01:36 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  42. 2026-10-22 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  43. 2026-10-22 02:48 UTCEchelonGraph re-scored
  44. 2026-10-22 02:48 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  45. 2026-10-21 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  46. 2026-10-21 03:59 UTCEchelonGraph re-scored
  47. 2026-10-21 03:59 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  48. 2026-10-20 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  49. 2026-10-20 05:08 UTCEchelonGraph re-scored
  50. 2026-10-20 05:08 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  51. 2026-10-19 16:27 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  52. 2026-10-19 06:17 UTCEchelonGraph re-scored
  53. 2026-10-19 06:17 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  54. 2026-10-18 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  55. 2026-10-18 07:28 UTCEchelonGraph re-scored
  56. 2026-10-18 07:28 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  57. 2026-10-17 16:28 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  58. 2026-10-17 08:39 UTCEchelonGraph re-scored
  59. 2026-10-17 08:38 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  60. 2026-10-16 16:32 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  61. 2026-10-16 09:49 UTCEchelonGraph re-scored
  62. 2026-10-16 09:49 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  63. 2026-10-15 16:27 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  64. 2026-10-15 09:25 UTCEchelonGraph re-scored
  65. 2026-10-15 09:25 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  66. 2026-10-14 16:28 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  67. 2026-10-14 05:42 UTCEchelonGraph re-scored
  68. 2026-10-14 05:42 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  69. 2026-10-13 16:28 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  70. 2026-10-13 00:56 UTCGHSA enrichmentGHSA-8v45-9mw2-ffmm
  71. 2026-10-12 19:47 UTCEchelonGraph re-scored
  72. 2026-10-12 16:29 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  73. 2026-10-12 00:10 UTCEchelonGraph re-scored
  74. 2026-10-11 13:42 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  75. 2026-10-10 19:56 UTCEPSS rescoreEPSS 1.4% · 70th percentile

Frequently asked(5)

What is CVE-2020-12886?
CVE-2020-12886 is a critical-severity vulnerability; its CVE record was published on June 18, 2020. 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() parses the CoAP packet header starting from the message token. The length of the token in the received message…
When was CVE-2020-12886 made public?
CVE-2020-12886 was made public on May 5, 2020: that is the date its CVE record's CNA, MITRE Corporation, gives for when the vulnerability was made public. The CVE record itself was published on June 18, 2020. EchelonGraph's copy of the record carries a last-modified date of November 21, 2024; the record at its source may have been updated since.
Is CVE-2020-12886 actively exploited?
CVE-2020-12886 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.4% probability of exploitation in the next 30 days (71st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-12886?
CVE-2020-12886 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2020-12886?
A fix for CVE-2020-12886 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2020-12886

Explore →

Is Your Infrastructure Affected by CVE-2020-12886?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.