CVE-2017-20285

CRITICALPre-NVD 9.19.1
EchelonGraph scoreHIGH confidence

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

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-10-05. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 5 sources updated this week

Also known asEUVD-2017-19016 (ENISA EUVD) · GHSA-c454-fc94-q86x (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Fixed versions, as the CVE record's CNA (CPAN Security Group) states them: "Upgrade to YAML 1.30 or later."

YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes.

A perl/hash:Class tag blesses a hash into the class it names. The document supplies the object's fields, and Perl calls DESTROY when it goes out of scope.

What DESTROY does depends on the classes the process has loaded. With File::Temp::Dir from core Perl, it can delete a directory tree the document names.

CVSS v3
9.1
EG Score
9.1CRITICALhigh confidence
EG Risk
56
EG Risk 56/100

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.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (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
0.3%
EPSS %ILE
27th
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.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days 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; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). 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

October 5, 2026

Last Modified

October 6, 2026

Advisory Details (5)

Auto-updated Oct 6, 2026
Patch available.
Web page

oss-security - CVE-2017-20285: YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes

http://www.openwall.com/lists/oss-security/2026/10/05/8
Web page

YAML loader can run DESTROY method of object created with perl/* tag · Issue #176 · ingydotnet/yaml-pm · GitHub

https://github.com/ingydotnet/yaml-pm/issues/176

Vendor Advisories for CVE-2017-20285(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibyaml-perl (1.15-1ubuntu0.1~esm1) @ xenial2026-11-02ubuntu

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
libyaml-perl—
  • every version up to 1.30-1: fixed in 1.30-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
libyaml-perl—
  • every version up to 1.30-1: fixed in 1.30-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
libyaml-perl—
  • every version up to 1.30-1: fixed in 1.30-1
—

Weakness Classification(2)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 27× in last 7d / 137× 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 it from the CNA feed. 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). Most recent first.

Showing the most recent 100 of 137 refreshes 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 37 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:34 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  2. 2026-11-02 16:25 UTCOSV refresh
  3. 2026-11-02 00:31 UTCEG score recompute
  4. 2026-11-02 00:31 UTCVendor advisory
  5. 2026-11-02 00:31 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  6. 2026-11-01 16:28 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  7. 2026-11-01 01:26 UTCEG score recompute
  8. 2026-11-01 01:26 UTCVendor advisory
  9. 2026-11-01 01:26 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  10. 2026-10-31 16:27 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  11. 2026-10-31 02:20 UTCEG score recompute
  12. 2026-10-31 02:20 UTCVendor advisory
  13. 2026-10-31 02:20 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  14. 2026-10-30 16:27 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  15. 2026-10-30 03:15 UTCEG score recompute
  16. 2026-10-30 03:15 UTCVendor advisory
  17. 2026-10-30 03:15 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  18. 2026-10-29 16:27 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  19. 2026-10-29 04:10 UTCEG score recompute
  20. 2026-10-29 04:09 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  21. 2026-10-28 16:27 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  22. 2026-10-28 04:59 UTCEG score recompute
  23. 2026-10-28 04:59 UTCVendor advisory
  24. 2026-10-28 04:59 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  25. 2026-10-27 16:26 UTCEPSS rescoreEPSS 0.3% · 27th percentile
Show 75 more
  1. 2026-10-27 05:54 UTCEG score recompute
  2. 2026-10-27 05:54 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-10-26 16:26 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  4. 2026-10-26 02:45 UTCVendor advisory
  5. 2026-10-26 02:44 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  6. 2026-10-25 19:35 UTCEG score recompute
  7. 2026-10-25 16:27 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  8. 2026-10-25 03:36 UTCEG score recompute
  9. 2026-10-25 03:36 UTCVendor advisory
  10. 2026-10-25 03:36 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  11. 2026-10-24 16:27 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  12. 2026-10-24 04:31 UTCEG score recompute
  13. 2026-10-24 04:31 UTCVendor advisory
  14. 2026-10-24 04:31 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  15. 2026-10-23 16:26 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  16. 2026-10-23 05:25 UTCEG score recompute
  17. 2026-10-23 05:25 UTCVendor advisory
  18. 2026-10-23 05:25 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  19. 2026-10-22 16:27 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  20. 2026-10-22 06:17 UTCEG score recompute
  21. 2026-10-22 06:16 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  22. 2026-10-21 16:27 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  23. 2026-10-21 07:08 UTCEG score recompute
  24. 2026-10-21 07:08 UTCVendor advisory
  25. 2026-10-21 07:08 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  26. 2026-10-20 16:27 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  27. 2026-10-20 08:02 UTCEG score recompute
  28. 2026-10-20 08:02 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  29. 2026-10-19 16:26 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  30. 2026-10-19 08:55 UTCEG score recompute
  31. 2026-10-19 08:55 UTCVendor advisory
  32. 2026-10-19 08:55 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  33. 2026-10-18 16:27 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  34. 2026-10-18 09:48 UTCEG score recompute
  35. 2026-10-18 09:48 UTCVendor advisory
  36. 2026-10-18 09:48 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  37. 2026-10-17 16:27 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  38. 2026-10-17 10:41 UTCEG score recompute
  39. 2026-10-17 10:41 UTCVendor advisory
  40. 2026-10-17 10:41 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  41. 2026-10-16 16:29 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  42. 2026-10-16 11:34 UTCEG score recompute
  43. 2026-10-16 11:34 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  44. 2026-10-15 16:26 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  45. 2026-10-15 12:17 UTCEG score recompute
  46. 2026-10-15 12:17 UTCVendor advisory
  47. 2026-10-15 12:17 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  48. 2026-10-14 16:27 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  49. 2026-10-14 07:42 UTCEG score recompute
  50. 2026-10-14 07:42 UTCVendor advisory
  51. 2026-10-14 07:42 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  52. 2026-10-13 16:27 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  53. 2026-10-13 02:55 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  54. 2026-10-12 20:29 UTCEG score recompute
  55. 2026-10-12 16:28 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  56. 2026-10-12 04:45 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  57. 2026-10-12 00:23 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  58. 2026-10-11 19:56 UTCEG score recompute
  59. 2026-10-11 19:56 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  60. 2026-10-11 15:36 UTCEG score recompute
  61. 2026-10-11 15:36 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  62. 2026-10-11 13:41 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  63. 2026-10-11 11:16 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  64. 2026-10-11 06:53 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  65. 2026-10-11 02:34 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  66. 2026-10-10 22:14 UTCEG score recompute
  67. 2026-10-10 22:14 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  68. 2026-10-10 19:55 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  69. 2026-10-10 17:53 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  70. 2026-10-10 13:34 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  71. 2026-10-10 09:14 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  72. 2026-10-10 04:51 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  73. 2026-10-10 00:31 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1
  74. 2026-10-09 20:12 UTCEG score recompute
  75. 2026-10-09 20:12 UTCGHSA enrichmentGHSA-c454-fc94-q86x · GitHub severity CRITICAL · GitHub CVSS 9.1

Frequently asked(5)

What is CVE-2017-20285?
CVE-2017-20285 is a critical-severity vulnerability; its CVE record was published on October 5, 2026. YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes. A perl/hash:Class tag blesses a hash into the class it names. The document supplies the object's fields, and Perl calls DESTROY when it goes out of scope. What DESTROY does depends on the…
When was the CVE record for CVE-2017-20285 published?
The CVE record for CVE-2017-20285 was published on October 5, 2026. 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 October 6, 2026; the record at its source may have been updated since.
Is CVE-2017-20285 actively exploited?
CVE-2017-20285 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (27th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2017-20285?
CVE-2017-20285 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2017-20285?
A fix for CVE-2017-20285 is available: update to the fixed version the vendor names in its advisory. Fixed versions, as the CVE record's CNA (CPAN Security Group) states them: "Upgrade to YAML 1.30 or later." The vendor advisories EchelonGraph has for CVE-2017-20285 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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