CVE-2020-36242

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 6.7% (93rd percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 6.7%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
48
EG Risk 48/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation7% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
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
6.7%
EPSS %ILE
93rd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or 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 (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact total (CVSS ≥ 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

February 7, 2021

Last Modified

November 21, 2024

Advisory Details (4)

Auto-updated Jul 22, 2026
Patch available.
generic

[SECURITY] Fedora 33 Update: python-cryptography-3.2.1-2.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L7RGQLK4J5ZQFRLKCHVVG6BKZTUQMG7E/
generic

Fernet fails to encrypt/decrypt large data · Issue #5615 · pyca/cryptography · GitHub

https://github.com/pyca/cryptography/issues/5615
generic

Comparing 3.3.1...3.3.2 · pyca/cryptography · GitHub

https://github.com/pyca/cryptography/compare/3.3.1...3.3.2
generic

cryptography/CHANGELOG.rst at main · pyca/cryptography · GitHub

https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst

Vendor Advisories for CVE-2020-36242(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
redhatrh-python38-python-urllib3-0:1.25.7-7.el72021-08-24redhat
redhatredhat-virtualization-host-0:4.4.6-20210527.3.el8_42021-06-03redhat
redhatpython-cryptography-0:3.2.1-4.el82021-05-18redhat

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)
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
py3-cryptography—
  • every version up to 3.3.2-r0: fixed in 3.3.2-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
py3-cryptography—
  • every version up to 3.2.2-r0: fixed in 3.2.2-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
py3-cryptography—
  • every version up to 3.2.2-r0: fixed in 3.2.2-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
python-cryptography—
  • every version up to 3.3.2-1: fixed in 3.3.2-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
python-cryptography—
  • every version up to 3.3.2-1: fixed in 3.3.2-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
python-cryptography—
  • every version up to 3.3.2-1: fixed in 3.3.2-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
python-cryptography—
  • every version up to 3.3.2-1: fixed in 3.3.2-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
cryptography3.1 ... 3.3.1 (6 versions)
  • 3.1 up to 3.3.2: fixed in 3.3.2
—

Weakness Classification(2)

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

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 7× in last 7d / 25× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 154 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2020-36242?
CVE-2020-36242 is a critical vulnerability published on February 7, 2021. In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.
When was CVE-2020-36242 disclosed?
CVE-2020-36242 was first published on February 7, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-36242 actively exploited?
CVE-2020-36242 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.7% probability of exploitation in the next 30 days (93rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-36242?
CVE-2020-36242 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2020-36242?
A fix for CVE-2020-36242 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2020-36242 are linked in the Vendor Advisories panel on this page.

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