CVE-2020-8165

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2020-05-26. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Elevated

Also known asEUVD-2020-0401 (ENISA EUVD) · GHSA-2p68-f74v-9wc6 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 46%CVSS: 9.8Exploit: Public PoCExposed services: Not assessed

A fix is available — apply it.

A deserialization of untrusted data vulnernerability exists in rails < 5.2.4.3, rails < 6.0.3.1 that can allow an attacker to unmarshal user-provided objects in MemCacheStore and RedisCacheStore potentially resulting in an RCE.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
62
EG Risk 62/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation46% × 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, Track* at medium and Attend at high mission impact.
Exploitation public PoC (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
46%
EPSS %ILE
98th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
46% 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, Track* at medium and Attend at high mission impact.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, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (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 19, 2020

Last Modified

May 9, 2025

Advisory Details (5)

Auto-updated Oct 9, 2026
Patch available.
Web page

[SECURITY] [DSA 4766-1] rails security update

https://www.debian.org/security/2020/dsa-4766
Web pageMentions a patch (unverified)

[SECURITY] [DLA 2282-1] rails security update

https://lists.debian.org/debian-lts-announce/2020/07/msg00013.html
Web pageMentions a patch (unverified)

[SECURITY] [DLA 2251-1] rails security update

https://lists.debian.org/debian-lts-announce/2020/06/msg00022.html

Vendor Advisories for CVE-2020-8165(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhattfm-rubygem-zeitwerk-0:2.2.2-1.el7sat2021-04-21redhat
rubygemsactivesupport @ 6.0.3.1 (fixes >= 6.0.0, <= 6.0.3)—ghsa
rubygemsactivesupport @ 5.2.4.3 (fixes >= 5.0.0, <= 5.2.4.2)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(8 across 8 ecosystems)
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
rails2:5.2.2.1+dfsg-1, 2:5.2.2.1+dfsg-1+deb10u1
  • every version up to 2:5.2.2.1+dfsg-1+deb10u2: fixed in 2:5.2.2.1+dfsg-1+deb10u2
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
rails—
  • every version up to 2:5.2.4.3+dfsg-1: fixed in 2:5.2.4.3+dfsg-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
rails—
  • every version up to 2:5.2.4.3+dfsg-1: fixed in 2:5.2.4.3+dfsg-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
rails—
  • every version up to 2:5.2.4.3+dfsg-1: fixed in 2:5.2.4.3+dfsg-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
rails—
  • every version up to 2:5.2.4.3+dfsg-1: fixed in 2:5.2.4.3+dfsg-1
—
Debian:8(1)
PackageVulnerable rangeFix by version rangeDependents
rails2:4.1.8-1 ... 2:4.1.8-1+deb8u6 (7 versions)
  • every version up to 2:4.1.8-1+deb8u7: fixed in 2:4.1.8-1+deb8u7
—
Debian:9(1)
PackageVulnerable rangeFix by version rangeDependents
rails2:4.2.7.1-1, 2:4.2.7.1-1+deb9u1, 2:4.2.7.1-1+deb9u2
  • every version up to 2:4.2.7.1-1+deb9u3: fixed in 2:4.2.7.1-1+deb9u3
—
RubyGems(1)
PackageVulnerable rangeFix by version rangeDependents
activesupport6.0.0 ... 6.0.3.rc1 (10 versions)
  • 5.0.0 up to 5.2.4.3: fixed in 5.2.4.3
  • 6.0.0 up to 6.0.3.1: fixed in 6.0.3.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 67× 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 230 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 130 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:39 UTCEPSS rescoreEPSS 46% · 98th percentile
  2. 2026-11-13 03:41 UTCEchelonGraph re-scored
  3. 2026-11-13 03:41 UTCVendor advisory
  4. 2026-11-13 03:41 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-11-12 16:29 UTCEPSS rescoreEPSS 46% · 98th percentile
  6. 2026-11-12 02:09 UTCEchelonGraph re-scored
  7. 2026-11-12 02:09 UTCVendor advisory
  8. 2026-11-12 02:08 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-11-11 16:31 UTCEPSS rescoreEPSS 46% · 98th percentile
  10. 2026-11-11 00:34 UTCEchelonGraph re-scored
  11. 2026-11-11 00:34 UTCVendor advisory
  12. 2026-11-11 00:34 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-10 16:34 UTCEPSS rescoreEPSS 46% · 98th percentile
  14. 2026-11-09 23:00 UTCEchelonGraph re-scored
  15. 2026-11-09 23:00 UTCVendor advisory
  16. 2026-11-09 23:00 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-09 16:29 UTCEPSS rescoreEPSS 46% · 98th percentile
  18. 2026-11-08 21:28 UTCEchelonGraph re-scored
  19. 2026-11-08 21:28 UTCVendor advisory
  20. 2026-11-08 21:28 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-08 16:32 UTCEPSS rescoreEPSS 46% · 98th percentile
  22. 2026-11-07 19:56 UTCEchelonGraph re-scored
  23. 2026-11-07 19:56 UTCVendor advisory
  24. 2026-11-07 19:56 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-07 16:33 UTCEPSS rescoreEPSS 46% · 98th percentile
Show 75 more
  1. 2026-11-06 18:23 UTCEchelonGraph re-scored
  2. 2026-11-06 18:23 UTCVendor advisory
  3. 2026-11-06 18:23 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-06 16:30 UTCEPSS rescoreEPSS 46% · 98th percentile
  5. 2026-11-05 16:51 UTCEchelonGraph re-scored
  6. 2026-11-05 16:51 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-11-05 16:30 UTCEPSS rescoreEPSS 46% · 98th percentile
  8. 2026-11-04 16:29 UTCEPSS rescoreEPSS 46% · 98th percentile
  9. 2026-11-04 15:18 UTCEchelonGraph re-scored
  10. 2026-11-04 15:18 UTCVendor advisory
  11. 2026-11-04 15:18 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-11-03 16:37 UTCEPSS rescoreEPSS 46% · 98th percentile
  13. 2026-11-03 14:25 UTCOSV refresh
  14. 2026-11-03 13:45 UTCEchelonGraph re-scored
  15. 2026-11-03 13:45 UTCVendor advisory
  16. 2026-11-03 13:45 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-02 11:59 UTCEchelonGraph re-scored
  18. 2026-11-02 11:59 UTCVendor advisory
  19. 2026-11-02 11:59 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-11-01 10:26 UTCVendor advisory
  21. 2026-11-01 10:26 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-11-01 08:35 UTCGHSA enrichmentGHSA-2p68-f74v-9wc6 · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-11-01 08:35 UTCEchelonGraph re-scored
  24. 2026-10-31 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  25. 2026-10-31 08:53 UTCEchelonGraph re-scored
  26. 2026-10-31 08:53 UTCVendor advisory
  27. 2026-10-30 16:29 UTCEPSS rescoreEPSS 46% · 98th percentile
  28. 2026-10-30 07:20 UTCEchelonGraph re-scored
  29. 2026-10-30 07:20 UTCVendor advisory
  30. 2026-10-29 16:29 UTCEPSS rescoreEPSS 46% · 98th percentile
  31. 2026-10-29 05:47 UTCEchelonGraph re-scored
  32. 2026-10-29 05:47 UTCVendor advisory
  33. 2026-10-28 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  34. 2026-10-28 04:15 UTCEchelonGraph re-scored
  35. 2026-10-28 04:15 UTCVendor advisory
  36. 2026-10-27 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  37. 2026-10-27 02:31 UTCEchelonGraph re-scored
  38. 2026-10-27 02:31 UTCVendor advisory
  39. 2026-10-26 16:27 UTCEPSS rescoreEPSS 46% · 98th percentile
  40. 2026-10-25 20:54 UTCVendor advisory
  41. 2026-10-25 18:39 UTCEchelonGraph re-scored
  42. 2026-10-25 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  43. 2026-10-24 19:21 UTCEchelonGraph re-scored
  44. 2026-10-24 19:21 UTCVendor advisory
  45. 2026-10-24 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  46. 2026-10-23 17:49 UTCEchelonGraph re-scored
  47. 2026-10-23 17:49 UTCVendor advisory
  48. 2026-10-23 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  49. 2026-10-22 16:29 UTCEPSS rescoreEPSS 46% · 98th percentile
  50. 2026-10-22 16:15 UTCEchelonGraph re-scored
  51. 2026-10-22 16:15 UTCVendor advisory
  52. 2026-10-21 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  53. 2026-10-21 14:07 UTCEchelonGraph re-scored
  54. 2026-10-21 14:07 UTCVendor advisory
  55. 2026-10-20 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  56. 2026-10-20 12:35 UTCEchelonGraph re-scored
  57. 2026-10-20 12:35 UTCVendor advisory
  58. 2026-10-19 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  59. 2026-10-19 11:02 UTCEchelonGraph re-scored
  60. 2026-10-19 11:02 UTCVendor advisory
  61. 2026-10-18 07:54 UTCEchelonGraph re-scored
  62. 2026-10-18 07:54 UTCVendor advisory
  63. 2026-10-17 06:19 UTCEchelonGraph re-scored
  64. 2026-10-17 06:19 UTCVendor advisory
  65. 2026-10-16 16:33 UTCEPSS rescoreEPSS 46% · 98th percentile
  66. 2026-10-16 04:47 UTCEchelonGraph re-scored
  67. 2026-10-16 04:47 UTCVendor advisory
  68. 2026-10-15 16:27 UTCEPSS rescoreEPSS 46% · 98th percentile
  69. 2026-10-15 03:11 UTCEchelonGraph re-scored
  70. 2026-10-15 03:11 UTCVendor advisory
  71. 2026-10-14 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  72. 2026-10-13 23:23 UTCEchelonGraph re-scored
  73. 2026-10-13 23:23 UTCVendor advisory
  74. 2026-10-13 16:28 UTCEPSS rescoreEPSS 46% · 98th percentile
  75. 2026-10-12 19:31 UTCVendor advisory

Publicly available exploits

(2 references)

Public exploit code is referenced for this CVE (2 GitHub PoCs). Defenders should treat patch urgency accordingly.

Frequently asked(5)

What is CVE-2020-8165?
CVE-2020-8165 is a critical-severity vulnerability; its CVE record was published on June 19, 2020. A deserialization of untrusted data vulnernerability exists in rails < 5.2.4.3, rails < 6.0.3.1 that can allow an attacker to unmarshal user-provided objects in MemCacheStore and RedisCacheStore potentially resulting in an RCE.
When was the CVE record for CVE-2020-8165 published?
The CVE record for CVE-2020-8165 was published on June 19, 2020. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of May 9, 2025; the record at its source may have been updated since.
Is CVE-2020-8165 actively exploited?
CVE-2020-8165 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 46% probability of exploitation in the next 30 days (98th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-8165?
CVE-2020-8165 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2020-8165?
A fix for CVE-2020-8165 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2020-8165 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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